FERTILITY  AND  FERTILIZER  HINTS 


Published  by  ^ 

The    Chemical    Publishing    Co.   | 

Easton,  Penna. 


fij                                    Publishers  of  Scientific  Books  M 

k^  iHi 

1^     Engineering  Chemistry                          Portland  Cement  K| 

g     Agricultural  Chemistry                      Qualitative  Analysis  g 

Household  Chemistry              Chemists'  Pocket  Manual  || 

Metallurgy,  Etc.  | 

(^£^^-ZXi££ZS-Z'Z']^^2-Z^SZZ£Z^^ZZ^^^ZSS2'XS^'Z^^Z^£XiS 


Fertility 


and 


Fertilizer  Hints 


By 


JAMES  EDWARD  HALLIGAN 


CHEMIST  IN   CHARGE.   LOUISIANA  STATE  EXPERIMENT  STATION 


EASTON,  PA. 

THE    CHEMICAL    PUBLISHING    CO. 

1911 


LONDON,    ENGLAND: 

WILLIAMS  &  NORGATE 

14    HENRIETTA    STREET,    COVENT   GARDEN,   W.   C. 


,1.^ 


-b 


A6R1C, 
IIBRARY 


Copyright,    191  i,  by  Edward  Hart. 


PREFACE. 

The  little  book  is  an  abridged  edition  of  the  author's,  Soil 
Fertility  and  Fertilizers.  The  symbol*  has  been  used  throughout 
the  text  to  refer  to  notes,  in  the  back  of  the  book,  that  state  the 
topics  of  subject  matter  that  have  necessarily  been  omitted  in 
this  work. 

This  book  has  been  written  to  be  within  the  reach  of  the 
farmer,  student,  or  any  other  person  interested  in  the  subject, 
"Fertilizers,"  and  should  more  complete  data  be  desired  the 
unabridged  edition,  Soil  Fertility  and  Fertilizers  should  be  con- 
sulted. 

The  writer  is  indebted  to  the  Louisiana  Experiment  Station, 
for  illustrations. 

J.  E.  HALLIGAN. 
Baton  Rouge,  La. 


247081 


CONTENTS. 


CHAPTER  I— Chemical  Elements  Needed  by  Plants 

and  the  Composition  of  Plants 1-12 

The  Fifteen  Elements.  How  Plants  Feed.  The  Food 
of  the  Plant.  Composition  of  Plants.  Amounts  of 
Water  Used  by  Plants.  Water  in  Young  and  Mature 
Plants.  Dry  Matter  of  Plants.  Composition  of  the 
Dry  Matter  of  Plants.  Acids  and  Bases.  Salts.  Vari- 
ation of  Ash.  Occurrence  of  Mineral  Elements  in 
Plants.  Distribution  of  Ash  in  Plants.  Ash  of  Young 
and  Mature  Plants. 

CHAPTER  II— The  Fertility  of  the  Soil 13-24 

Composition  of  Soils.  Factors  Influencing  Soil  Fer- 
tility. The  Plant  Food  Supply.  Plant  Food  Removed 
by  Some  Crops.  Plant  Food  not  Available.  The  Es- 
sential Elements.  One  Element  Cannot  Replace  An- 
other. Physical  Condition  of  the  Soil.  Temperature. 
Mechanical  Composition.  Surface  Area  of  Soil  Grains. 
Lumpy  Soil.  Cracking  of  Soils.  Puddling  of  Soils. 
Freezing  and  Thawing.  Plants  are  Benefited  by  Open 
Soils.  Plants  Must  Have  Room.  Plants  Require 
Oxygen.  Drainage.  Capillary  Water.  The  Biological 
Condition  of  the  Soil.  The  Number  of  Bacteria  in  the 
Soil.  Nitrification.  Denitrification.  Organisms  that 
Gather  Nitrogen.     Inoculation  of  the  Soil. 

CHAPTER  III— Maintaining  Soil  Fertility     25-34 

Erosion  and  Ways  to  Check  It.  Loss  of  Fertility  b}' 
Drainage.  Fallowing.  Loss  of  Nitrogen  by  Continu- 
ous Cropping.  Losses  of  Phosphoric  Acid  and  Potash. 
One  Crop  Farming.  Diversification  and  Rotation  of 
Crops.  Make  up  of  a  Rotation.  Reasons  for  Rotating 
Crops.  Rotation  Keeps  Down  Weeds.  Legumes  are 
Profitable.  Rotation  Helps  to  Distribute  Farm  Labor. 
Rotation  Helps  to  Check  or  Eradicate  Insects  and 
Plant  Diseases.  It  Furnishes  Feed  for  Live  Stock.  It 
Allows  a  Regular  Income.  It  Prevents  Losses  of  Fer- 
tility. It  Utilizes  Plant  Food  More  Evenly.  It  Saves 
Fertilizer  Expenditure.  It  Regulates  the  Humus  Sup- 
ply.    System  of  Farming. 


CONTENTS  V 

CHAPTER  IV— Farm  Manures 35-47 

Kind  of  Manure.  Conditions  Affecting  the  Value  of 
Manure.  The  Age  of  the  Animal.  The  Use  of  the 
Animal.  The  Kind  of  Bedding  and  Amount  Influences 
the  Value  of  Manure.  Straw.  Leaves.  Sawdust.  Peat. 
Absorptive  Power  of  Bedding.  Hor.se  Manure.  Cow 
Manure.  Hog  Manure.  Sheep  Manure.  Hen  Ma- 
nure. Analyses  of  Farm  Manures.  How  to  Calculate 
the  Amount  of  Manure  Produced.  The  Nature  and 
Amount  of  Feed  Used  Affects  the  Value  of  Manure. 
Lasting  Effect  of  Manure.  Care,  Preservation,  and 
Use  of  Manure.  Waste  of  Manure.  Leaching.  Fer- 
mentations. Keep  Manure  Moist.  Composting  Ma- 
nure. Store  Manure  Under  Cover.  Preservatives. 
Physical  Effects  of  Manure.  Manure  Produces  a  Bet- 
ter Moisture  Condition.  It  Improves  the  Texture  of 
the  Soil.  It  Prevents  Mechanical  Loss  by  Winds.  It 
Benefits  Grass  Land.  Bacteriological  Effects  of  Ma- 
nure. Time  to  Apply.  Amount  to  Apply.  How  to 
Apply. 

CHAPTER  V  High  Grade  Nitrogenous  Materials..  48-59 
Forms  of  Nitrogen.  The  Meaning  of  the  Form  of 
Nitrogen.  The  Vegetable  Substances.  Cotton-Seed 
Meal.  Composition  of  Cotton-Seed  Meal.  Value  of 
Cotton-Seed  Meal.  Linseed  Meal.  Castor  Pomace. 
The  Chief  Animal  Substances.  Dried  Blood.  Tankage. 
Grades  of  Tankage.  Variation  in  Tankage.  Azotin. 
Steamed  Horn  and  Hoof  Meal.  Dry  Ground  F'i.sh. 
King  Crab.  Guano.  Ammonium  Sulphate.  Compo- 
sition and  Availability.  Nitrate  of  Soda.  Composition 
and  Properties  of  Nitrate  of  Soda.  Calcium  Nitrate. 
Calcium  Cyanamid.  Properties  of.   Fertilizing  Value  of. 

CHAPTER  VI     Low    Grade    Nitrogenous    Materials 

and  Functions  of  Nitrogen 60-69 

Raw  Leather  Meal.  Dissolved  Leather.  Feather 
Waste.  Hair  and  Fur  Waste.  Mora  Meal.  Beet 
Refuse.  Scutch.  Horn  and  Hoof  Meal.  Wool  Waste, 
Shoddies,  Etc.  Garbage  Tankage.  Dried  Peat.  Avail- 
ability of  Nitrogenous  Materials.  Value  of  Low  Grade 
Materials.  Use  of  Low  Grade  Materials  is  Increasing. 
Nitrogenous  Materials  to  Use.  Functions  of  Nitrogen. 
Excessive  Nitrogen  Invites  Diseases. 


VI  CONTEXTS 

CHAPTER  VII- Phosphates 70-79 

Bones.  Raw  Bone-Meal.  Steamed  Boiie-Meal.  De- 
gree of  Fineness.  Bone-Black.  Bone-Asli.  Bone 
Tankage.  Dry  Ground  Fish.  Mineral  Phosphates. 
South  Carolina  Phosphates.  Florida  Phosphates. 
Tennessee  Phosphates.  Canadian  Apatite.  Rodunda 
Phosphate.  Basic  Slag.  Phosphatic  Guanos.  Classifi- 
cation of  Phosphates.  Form  of  the  Phosphates. 
Availability  of  the  Phosphates. 

CHAPTER  VIII— vSuperphcsphates  and  Effect  of  Phos- 
phoric Acid 80-89 

Manufacture  of  Super  or  Acid  Phosphate.  Phosphates 
of  Lime.  Insoluble  Phosphoric  Acid.  Soluble  Phos- 
phoric Acid.  Reverted  Phosphoric  Acid.  Basic  Slag 
Phosphate.  Value  of  Reverted  Phosphoric  Acid.  Dif- 
ference Between  Phosphate  and  Superphosphate. 
Names  Applied  to  Superphosphates.  Available  Phos- 
phoric Acid.  The  Difference  in  the  Forms  of  Phosphoric 
Acid  in  Superphosphates.  Some  People  F'avor  Bone 
Superphosphates.  Double  Superphosphates.  No  Free 
Acid  in  Treated  Phosphates.  The  Color  of  an  Acid 
Phosphate.  How  to  Made  Superphosphate  at  Home. 
Amount  of  Phosphoric  Acid  in  Soils.  Fixation  of 
Phosphoric  .A.cid.  Inunctions  of  Phosphoric  Acid. 
The  Kind  of  Phosphate  to  Use. 

CHAPTER  IX— Potash  Fertihzers 90-97 

Potash  Salts  (Stassfurt).  History  of.  Kinds  of. 
Kainit.  Sylvinit.  Muriate  of  Potash.  Sulphate  of 
Potash.  Double  Sulphate  of  Potash  and  Magnesia. 
Potash  Manure  Salts.  Potassium-Magnesium  Car- 
bonate. Potash  from  Organic  Sources.  Wood  Ashes. 
Value  of  Wood  Ashes.  Tobacco  Stems  and  Stalks. 
Cotton-Seed  Hull  Ashes.  Carbonate  of  Potash.  Beet 
Molasses.  Amount  of  Potash  in  Soils.  Forms  of 
Potash.  Fixation  of  Potash.  Functions  of  Potash. 
Potash  Favors  Seed  Formation.  It  Effects  the  Leaves 
and  Maturity.  It  Neutralizes  Plant  Acids.  It  Checks 
Insect  Pests  and  Plant  Diseases. 

CHAPTER  X — Miscellaneous  F'ertilizer  Materials.  .  .  .      98-103 
Compost.     Seaweed.      Marl.      Peat   and    Muck.      Pul- 
verizeii  Manures.     Fresh  Fish  and  P'resh  Fish  Wastes. 
Sewage  and  Sewage  Sludge.     Coal  Ashes.     Lime   Kiln 
.\shes.     Rice    Hull    .\shes.     Corn    Cob    Ashes.      Brick 


CO.\Tl-:.\TS  vu 

Kiln  Ashes.  Soot.  Street  Sweepinjrs.  Potassium 
Nitrate.  Amtnoiiiuni  Nitrate.  Silicate  of  Potash. 
Iron  Sulphate.  Common  Salt.  Powder  Waste.  Sul- 
phates of  Magnesia  and  Soda.  Carbonate  of  Magne.sia. 
Ammonium  Chloride.     Manganese  Salts. 

CHAPTER  XI — Lime,  Gypsum  and  Green  Manures.  .  104-1 1 1 
Lime.  Forms  of.  When  Soils  Need  Lime.  How  to 
Find  Out  When  Soils  are  Acid.  How  to  Apply  Lime. 
The  Form  to  Use.  Amount  of  Lime  to  Apply.  Le- 
gumes Require  an  Alkaline  Soil.  Mechanical  Action 
of  Lime.  Lime  Decrea.ses  the  Action  of  Some  Fungus 
Diseases.  Gas  Lime.  Gypsum.  Green  Manures. 
Classes  of.  The  Best  Time  to  Plow  Under  a  Green 
Manure.  The  Time  to  Grow  a  Green  Manure.  Deep 
Rooted  Plants  Valuable. 

CHAPTER  XII— Commercial  Fertilizers 1 12-1 18 

Causes  of  the  Large  Consumption  of  Fertilizers.  Fer- 
tilizer Materials  Used  by  Manufacturers.  Basis  of  Pur- 
chase. Unit  and  Ton  Basis.  Fertilizer  Laws.  The 
Meaning  and  the  Interpretation  of  the  Guarantee. 

CHAPTER  XIII— Valuation  of  Fertilizers 1 19-125 

Interpretation  of  Chemical  Analyses.  Agricultural 
Values.  Commercial  Values.  Trade  Values.  How 
Obtained.  A  Discussion  of  the  Table  of  Trade  Values. 
How  to  Calculate  Commercial  Values. 

CHAPTER  XIV— Home  Mixtures 126-133 

Definitions.  Manufacturers'  Claims  Against  Home 
Mixing.  Reasons  Why  Farmers  Should  Mix  Fertili- 
zers at  Home.  Home  Mixing  Acquaints  the  Farmer 
with  Materials  Used.  Home  I\(ixing  Does  Away  With 
the  Purchase  of  Unnecessary  Constituents.  How  to 
Mix  Fertilizers  at  Home.  How  to  Calculate  Percent- 
ages from  Known  Amounts.  How  to  Calculate 
Amounts  from  Known  Percentages. 

CHAPTER  XV— A  Few  Remarks  about  Fertilizers  .  .  134-143 
Brand  and  Trade  Names.  How  to  Purchase  a  Ferti- 
lizer. Study  the  Guarantee.  Fertilizers  Should  Reach 
their  Guarantees.  Fertilizers  do  not  Deteriorate  Much 
on  Standing.  The  Time  to  Apply  Fertilizers.  How 
Fertilizers  are  Applied.  Is  it  Profitable  to  Use  Fer- 
tilizers?    Amount  of  Fertilizer  to  use. 


CHAPTER  I. 


CHEMICAL  ELEMENTS  NEEDED  BY  PLANTS  AND  THE  COMPO- 
SITION OF  PLANTS. 

In  order  to  thoroughly  understand  the  subject  "fertiUzers," 
we  must  become  familiar  with  the  chemical  elements  needed 
by  plants. 

There  are  about  8i  chemical  elements  known  to  us,  but  only 
15  of  these  are  required  for  plant  life  so  far  as  we  know. 

The  Fifteen  Elements. — Hydrogen,  oxygen,  nitrogen,  carbon, 
potassium,  phosphorus,  calcium,  sulphur,  silicon,  iron,  chlorine, 
magnesium,  sodium,  aluminum  and  manganese  are  the  elements 
used  by  plants.  Hydrogen,  oxygen,  nitrogen  and  chlorine,  in 
the  pure  state,  generally  occur  as  gases,  w^hile  the  other  ele- 
ments are  solids. 

The  Symbols. — The  chemist  uses  the  following  symbols  for  these 
elements. 

Hydrogen  (H)  Oxygen  (O)  Nitrogen  (N) 

Carbon  (C)  Potassium  ( K  )  Phosphorus  ( P ) 

Calcium  (Ca)  Sulphur  (S)  Silicon  (Si) 

Iron  (Fe)  Chlorine  (CI)  Magnesium  (Mg) 

Sodium  (Na)  Aluminum  (  Al)  Manganese  (Mn) 

Small  amounts  of  oxygen  are  sometimes  used  by  plants  in  the 
elementary  state.  Certain  plants  also  use  nitrogen  in  the  free 
state.  All  other  elements,  and  generally  oxygen  and  nitrogen 
must  be  combined  with  other  of  these  elements  to  be  favorable 
for  the  support  of  plant  life. 

Hydrogen. — This  is  a  colorless  invisible  gas,  having  no  smell 
or  taste.  It  is  generally  found  in  combination  with  other  ele- 
ments as  water,  hydrochloric  acid,  marsh  gas,  sulphuretted  hy- 
drogen, all  acids  and  most  organic  (animal  and  vegetable)  com- 
pounds. It  is  mo.st  commonly  found  as  water  (HoO),  which 
is  the  most  necessary  food  of  the  plant.  In  the  free  state  hydro- 
gen occurs  only  in  small  quantities  upon  the  earth  in  the  gases 
of  petroleum  w-ells,  around  volcanic  eruptions,  and  it  is  evolved 
by  the  fermentation  and  decomposition  of  some  organic  sub- 
stances. 


2  FERTII.ITV    AND   FERTILIZER    IIIXTS 

Oxygen. — In  the  free  gaseous  state,  about  one-fifth,  by  bulk, 
of  the  atmosphere  is  made  up  of  this  element,  mechanically 
mixed  with  nitrogen.  It  is  found  in  enormous  quantities  in 
combination  with  other  elements.  It  constitutes  about  eight- 
ninths  b}'  weight  of  water  and  nearly  one-half  of  the  earth's 
crust.  All  combustion  and  decay  require  oxygen.  The  plant 
stores  up  oxygen  in  combination  with  other  elements  and  with- 
out oxygen  plants  would  die.  The  plant  takes  in  oxygen,  from 
the  atmosphere,  in  combination  with  carbon,  as  carbonic  acid 
gas,  through  the  openings  on  the  under  sides  of  the  leaves ;  the 
carbon  is  absorbed  and  the  excess  of  oxygen  given  off.  Oxygen 
combines  with  most  other  elements  forming  oxides.  It  often 
combines  with  other  elements  in  varied  amounts  forming  oxides 
of  dift'erent  composition  which  are  generally  quite  stable.  The 
color  of  soils  is  often  determined  by  oxides  such  as  iron  oxides. 
The  iron  oxides  influence  the  moisture  condition  of  soils  be- 
cause of  their  absorptive  qualities  and  help  to  oxidize  organic 
substances  in  the  soil.  The  roots  of  plants  when  deprived  of  air 
in  the  soil  are  able  to  draw  upon  iron  oxides  for  oxygen. 

Nitrogen. — About  four-fifths  of  the  atmosphere,  or  about  35,000 


m 

^ 

^^ 

^ 

m 

^^# 

MK^fi 

MMMm& 

^i^ 

i 

(OfaP^B 

1^ 

^^P 

^^^ 

CHI 

m^r 

rig.  I. — Cowpeas  liave  the  power  of  gathering  nitrogen  from  the  air. 

tons  over  every  acre  of  land,  is  made  up  of  nitrogen  in  the  free 


CUKMICAL  KLKMKNTS   NEEDKO  llV   PLANTS  .^ 

gaseous  state.  In  combination  this  element  is  found  in  many 
substances  such  as  ammonia,  sodium  nitrate  (Chile  saltpeter), 
potassium  nitrate  and  many  organic  compounds.  Certain  plants, 
namely  the  legumes,  of  which  the  pea,  bean,  alfalfa,  clovers, 
covvpea,  soy  bean,  etc.,  are  members,  have  the  power  of  gather- 
ing nitrogen  from  the  air,  by  means  of  certain  growths  (tuber- 
cles )  on  their  roots. "^  Although  nitrogen  is  abundant  in  the  free 
state  it  cannot  be  used  as  such  by  most  plants  and  it  must  be 
combined  with  other  elements  to  be  available  as  ])lant  food. 
Nitrogen  as  sold  in  fertilizers  is  in  combination  with  other  ele- 
ments, and  is  the  most  fugitive  and  expensive  of  the  essential 
elements.     This  will  be  described  more  fully  later  on. 

Carbon. — This  element  is  found  in  the  free  state  in  charcoal, 
graphite  and  diamonds.  In  coal  it  is  also  present  in  an  impure 
state.  Muck  and  peat  contain  considerable  carbon.  Humus 
(the  decayed  organic  matter  in  soils)  is  made  up  partly  of  car- 
bon. In  combination  with  oxygen  we  find  carbon  as  carbon 
dioxide  (carbonic  acid  gas)  in  the  air.  It  is  present  in  greater 
quantities  in  plant  life  than  any  other  element.  Henry^  says: 
"10,000  volumes  of  air  contain  about  3  volumes  of  carlx)nic  acid 
gas ;  32  cubic  yards  of  air  hold  one  pound  of  this  gas.  An  acre 
of  growing  wheat  will  gather  during  four  months,  2,000  pounds 
of  carbonic  acid  gas,  or  an  amount  equal  to  all  the  air  contains 
over  the  same  area  of  land  to  a  height  of  three  miles."  All 
of  our  farm  crops  use  a  great  amount  of  carbon  in  the  form  of 
carbonic  acid  gas.  All  carbonates  (limestone,  chalk,  marble, 
shells,  etc.)  and  all  organic  substances  contain  carbon.  The  car- 
bonates of  lime  found  in  the  soil  exert  a  great  influence  upon  the 
conversion  of  some  forms  of  nitrogen  into  available  plant  food 
and  in  the  general  physical  condition  of  the  soil. 

Potassium  in  combination  is  very  common.  It  is  mined  in  large 
quantities  as  potas.sium  salts  in  the  Stassfurt  mines  of  Germany. 
The  presence  of  this  element  in  wood  ashes,  as  potassium  car- 
bonate, makes  this  substance  a  valuable  fertilizer.  Potassium 
is  found  in  most  rocks  and  soils.  In  plants  it  is  associated  with 
organic    acids.     It    is    found   in    sea   water   and    saltpeter.     This 

1  Feeds  and  Feeding. 


4  FICRTII^ITY    AND   FERTILIZER    HINTS 

element  is  essential  to  plant  growth  and  is  found  in  the  stems, 
leaves  and   fruits  of  plants. 

Phosphorus  is  found  in  combination  with  oxygen  and  metals, 
as  phosphates.  Vast  deposits  of  phosphates  are  found  in  Tennes- 
see, South  Carolina,  Florida  and  some  of  the  western  states. 
It  is  present  in  many  rocks  and  most  soils  and  is  an  important 
element  for  plant  food.  It  exists  in  combination  with  organic 
substances  in  plants  and  constitutes  an  important  part  of  the  ash 
of  plants.  Bones,  which  contain  about  60-65  P^^"  cent,  of  cal- 
cium phosphate,  are  an  important  source  of  phosphorus  for  plant 
food. 

Calcium  is  an  element  which  occurs  in  combination  in  many 
substances  as  lime,  marble,  shells,  coral  and  gypsum.  It  makes 
up  about  one-sixteenth  part  of  the  earth's  crust.  Plants  and 
animals  require  this  element,  sometimes  in  larger  amounts  than 
one  would  imagine.  The  bones  of  animals  are  made  up  largely 
of  this  element  in  combination  as  lime.  Lime  is  a  great  factor 
in  regulating  the  physical  condition  of  soils. 

Sulphur. — This  is  a  yellow  substance  which  is  found  in  the 
free  state  in  large  deposits  in  Louisiana,  western  United  States, 
and  Sicily.  It  is  found  in  combination  in  gypsum  (an  important 
indirect  fertilizer),  pyrites  (a  source  of  sulphuric  acid),  galena, 
etc.  It  is  also  found  in  many  natural  waters.  In  plants  it  oc- 
cupies an  important  place,  occurring  in  organic  compounds  as 
protein,  or  nitrogenous  portions,  and  also  as  sulphuric  acid.  Most 
of  our  soils  are  sufficiently  supplied  with  this  element  for  the 
nourishment  of  plants. 

Silicon  occurs  in  combination  as  sand,  flint,  quartz,  etc.,  and 
constitutes  about  one-half  the  earth's  crust.  It  is  present  in  most 
rocks  and  soils  and  plays  an  important  part  in  the  physical  make 
up  of  the  soil.  Plants  require  this  element  to  support  certain 
parts  of  their  structure.  The  hulls  and  straws  of  plant  sub- 
stances are  often  comparatively  rich  in  this  element. 

Iron  is  a  very  common  element  and  in  combination  it  is  widely 
distributed.  Although  used  in  small  amounts  by  plants  it  is 
nevertheless  very  important,  as  it  is  necessary  for  the  produc- 
tion and  activity  of  chlorophyll   (the  green  coloring  matter  of 


CHEMICAL  ELEMKXTS   NEEDED  RV   PLANTS  5 

plants).  The  color  of  soils  (red  and  yellow)  are  chiefly  due  to 
the  presence  of  iron  compounds. 

Chlorine  is  most  commonly  found  as  chloride  (common  salt). 
It  also  occurs  in  combination  with  hydrogen,  as  hydrochloric  acid. 

Magnesium. — This  element  is  found  in  most  rocks  and  soils 
in  sufficient  amounts  for  the  needs  of  the  plant.  It  is  used  in 
different  parts  of  the  plant  but  mainly  in  the  formation  of  seeds. 

Sodium. — Chloride  is  the  commonest  compound  of  this  ele- 
ment and  is  present  in  common  salt,  sea  water,  salt  lakes,  and 
in  many  springs  and  waters.  It  occurs  in  sodium  carbonate  and 
sodium  nitrate ;  the  latter  compound  is  a  valuable  fertilizer  be- 
cause of  its  nitrogen  content.  Sodium  is  believed  to  be  helpful 
in  plant  growth. 

Aluminum. — This  element  is  the  most  widely  distributed  next 
to  oxygen  and  silicon  of  the  earth's  crust.  /Vbout  one-twelfth  of 
the  earth's  crust  is  aluminum.  In  combination  it  is  found  in  clay, 
slate,  kaolin,  etc.  Although  it  is  very  abundant  it  is  not  used 
much  by  plants. 

Manganese  occurs  in  combination  as  manganese  blend,  man- 
ganese spar,  manganite,  etc.  Plants  use  this  element  in  small 
amounts  although  it  is  not  believed  to  be  necessary  for  plant 
growth.* 

How  Plants  Feed.^ — Every  seed  is  made  up  of  a  germ  (embryo 
plant)  surrounded  by  stored  up  food.  When  a  seed  is  dropped 
into  the  warm  soil  it  germinates  and  feeds  on  this  stored  up 
food  material  until  it  has  put  forth  a  root,  stem  and  leaves.  It 
is  now  able  to  gather  its  food  from  the  air,  water  and  soil.  On 
the  roots  of  plants  are  minute  root  hairs,  composed  of  single 
cells,  which  absorb  food  materials  from  the  soil  water,  by  means 
of  osmosis  or  diffusion.  The  leaves,  on  the  under  sides,  have 
minute  openings  which  permit  the  breathing  of  air  which  con- 
tains carbonic  acid  gas.  The  carbon  is  used  in  building  up  the 
plant  and  the  excess  of  oxygen  is  given  back  to  the  atmosphere. 
This  process  requires  the  presence  of  light  as  does  chlorophyll 
(green   coloring  matter   of  plants).     Plants   will   grow    without 

1  Much   of  the  remaining   portion   of  this  chapter  has  been  taken  from    Halligan's 
Elementary  Treatise  On  Stock  Feeds  and  Feeding. 


6  FKRTILITY    AND   FERTILIZER    HINTS 

light  as  long  as  the  food  supply  in  the  seed  lasts,  but  they  will 
be  white  and  will  not  produce  seed.  By  the  aid  of  sunlight  the 
materials  gathered  by  the  root  hairs  and  leaves  are  manufactured 
into  compounds  and  retained  by  the  plants. 

The  Food  of  the  Plant. — The  plant  keeps  growing  until  it  pro- 
duces seed.  It  may  continue  its  growth  for  years  as  is  the  case 
with  trees.  In  this  continual  growing  process  we  cannot  see 
the  plant  feeding  but  we  know  its  nourishment  is  obtained  from 
the  soil,  water  and  air.  The  food  of  the  plant,  then,  consists  of 
the  mineral  substances,  water  and  gases  taken  from  the  soil  and 
air. 

Composition  of  Plants. — All  plants  are  made  up  of  water  and 
dry  matter.  The  water  is  composed  of  hydrogen  and  oxygen 
while  the  dry  matter  contains  many  elements  and  combinations 
of  elements. 

Water. — All  plants  and  parts  of  plants  contain  water.  The 
water  is  present  in  two  forms,  namely,  physiological  and  hygro- 
scopic. 

1.  Physiological  water  is  that  which  is  contained  in  the  plant 
structure.  It  is  obtained  from  the  soil.  It  is  used  to  keep  the 
leaf  tissues  and  their  cell  walls  moist  so  that  carbonic  acid  gas 
may  be  absorbed,  to  transfer  food  materials,  and  to  regulate  the 
temperature  of  the  plant  by  means  of  evaporation  of  water,  just 
as  the  temperature  of  the  animal  body  is  regulated  by  the  evapora- 
tion of  perspiration.  When  green  grass  is  dried  in  the  sun  the 
loss  in  weight  is  mostly  due  to  evaporation  of  physiological  water. 

2.  Hygroscopic  water  is  that  which  is  taken  up  from  the  air 
and  may  vary  from  day  to  day  according  to  the  humidity  of  the 
surrounding  air.  On  rainy  days  more  water  would  be  taken  up 
than  on  dry  days.  The  writer  has  often  determined  the  water 
content  of  the  same  samples  of  corn  meal,  wheat  bran,  cotton- 
seed meal,  hays,  etc.,  on  different  days  and  found  variations 
often  of  two  per  cent.  Sometimes  there  is  an  increase  and  at 
other  times  a  decrease  of  hygroscopic  water,  depending  upon  the 
humidity  of  the  surrounding  air.  The  hygroscopic  moisture  also 
varies  with  different  plant  materials. 


Clll'.MICAL 


:.M1{.\TS    NKKDl 


I'L.W 


Amounts  of  Water  Used  by  Plants. — Accordinsj;  to  Wliitson,  the 
amount  of  water  uslmI  l)y  plants  varies  greatly  with  the  kind  of 
plant  an;l  with  climatic  condititins,  hut  is  always  large.  For 
instance,  in  the  growth  of  one  ])()und  of  dry  matter  of  corn 
ahout  250  to  300  i^oiuids  of  water  are  used;  for  jxttatoes.  350 
to  400  pounds;  for  clover.  300  to  600  pounds. 

Amounts  of  Water  Exhaled  by  Plants.^ — 

One  acre  Pounds  of 

exhales  water 

Wheat 409,832 

Clover 1 ,096,234 

Sunflowers 12,585,994 

Cabbage 5,049- 194 

Grapevines 73".  733 

Hops 4,445,021 

Variation  of  Water  in  Plants. — Some  species  of  plants  contain 
much  more  water  than  others  and  the  different  parts  of  the 
same  plant  show  a  great  variation  in  water  content.  We  have 
all  no  doubt  noticed  that  certain  fruits  like  the  apple,  pear,  lemon, 
plum,  peach,  strawberry,  etc.,  and  roots  and  tubers  as  the  turnip, 
beet,  radish,  carrot,  Irish  potato,  etc..  contain  a  great  deal  of 
water.  Perhaps  some  have  not  heretofore  thought  that  sub- 
stances like  corn  grain,  wheat  kernel,  rice  kernel,  the  several 
grain  straws,  etc..  have  water  present.  The  following  table  gives 
us  the  percentage  of  water  in  some  familiar  plants  and  parts 
of  plants. 


Forage  plants  (green) 


Apple 

Grape 

Peach  

Pear 

Strawberry 


Roots  and  tubers 


Beet  (mangel) 

Carrot 

Irish  potato  . 
Sweet  potato- 
Turnip 


80.0 

83.0 
88.4 
83.1 
90.2 


90.9 
88.6 
78.9 
71. 1 
905 


Alfalfa  ■ . 
Corn .... 
Cow  pea  . 
Sorghutu 
Timothy 


Cereals  and  stra\ 


Corn  (grain) 
Oats  (grain) 
Rice  ( rough ) 

Rye  straw 

Wheat  straw 


7r.8 
79-3 
83.6 
79-4 
61.6 


10.6 
I  i.o 
10.9 
7-1 
9.6 


Stockbridge,  Rock  and  .Soils. 
2 


8  FERTILITY   AND  FERTILIZER    HINTS 

Water  in  Young  and  Mature  Plants. — The  percentage  of  water 
in  young  plants  is  greater  than  in  mature  plants.  This  is  easily 
accounted  for  because  the  young  plant  uses  a  great  deal  of  water 
in  transferring  food  materials  required  for  its  growth.  The 
Maine  State  College  conducted  an  investigation  on  timothy  with 
the  following  results  •} 

Water  Water 

Per  cent.  Per  cent. 

Nearly  headed  out 78.7         Out  of  blossom 65.2 

In  full  blossom 71.9         Nearly  ripe 63.3 

The  results  on  timothy  are  similar  to  what  would  be  found 
with  other  plants.  It  follows  that  the  more  mature  a  plant  is, 
the  easier  it  is  to  field  cure. 

Active  cells  in  plants  contain  more  water  than  do  the  older 
or  less  active  cells  and  this  may  account  for  the  larger  per- 
centage of  water  found  in  young  plants. 

Dry  Matter  of  Plants. — As  previously  stated,  the  plant  is  made 
up  of  water  and  dry  matter.  When  water  is  driven  off  from 
plants  the  dry  matter  is  what  remains.  Now  if  we  burn  this 
dry  matter  a  larg-e  proportion  of  it  passes  off  in  the  form  of 
invisible  gases.  This  material  which  so  disappears,  in  burning, 
is  known  as  organic  matter,  that  which  is  left  is  the  ash  or 
mineral  matter  or  inorganic  matter.  The  organic  imatter  is 
composed  of  carbon,  hydrogen,  nitrogen,  oxygen,  etc.  The  ash 
is  made  up  of  soda,  phosphorus,  sulphur,  iron,  potassium,  cal- 
cium, silicon,  etc.''' 

We  may  express  the  composition  of  plants  as : 

Plants  I  Water  J  ^^j^ 

I  Dry  matter    |  o,g^„i^  „,3tter 

Composition  of  the  Dry  Matter  of  Plants. — A  German  scientist, 
Knop,  estimated ;  according  to  Jordan  :  "That  if  all  the  species 
of  the  vegetable  kingdom,  exclusive  of  the  fungi,  were  fused  into 
one  mass,  the  ultimate  composition  of  the  dry  matter  of  this  mix- 
ture would  be  the  following:" 

1  Jordan,  The  Feeding  of  Animal.s. 


CHKMICAL   KLlvMKNTS    NKKDKn  P.V    PLANTS  9 

Ver  cent. 

Carbon 45.0 

Oxygen 42.0 

Hydrogen 6.5 

Nitrogen 1.5 

Mineral  compounds  (ash) 5.0 

From  the  above  analysis  it  is  readily  seen  that  carbon  and 
oxygen  make  up  the  largest  proportion  of  plants.  Let  us  ex- 
amine the  composition  of  some  farm  products  that  are  familiar 
to  us,  and  find  out  if  this  same  predominance  of  carbon  and 
oxygen -exists. ^ 


Carbon 
Per  cent. 


Oxygen 
Per  cent. 


Hydrogen 
Per  cent. 


Nitrogen 
Per  cent. 


Ash 
Per  cent. 


Clover  hay 

Wheat  kernel  .... 

Fodder  beets 

Fodder  beet  leaves 
Wheat  straw 


47-4 
46.1 
42.8 
38.1 
48.4 


37.8 
43-4 
43-4 
30.8 
38.9 


5.0 
5-8 
58 
5.1 
5-3 


2-3 
1-7 
4-5 
0.4 


7-7 
2.4 

6.3 

21.5 

7.0 


There  is  some  variation  in  the  composition  of  these  farm 
products  but  the  carbon  and  oxygen  constitute  the  largest  amounts 
of  the  elements  present. 

This  predominance  of  carbon  and  oxygen  is  due  to  the  fact 
that  about  nineteen-twentieths  of  the  plants'  food  is  obtained 
from  air  and  water,  and  the  remaining  one-twentieth  is  derived 
from  mineral  compounds  of  the  soil  and  soil  water.  In  other 
words  the  farmer  only  has  to  supply  a  small  proportion  of  the 
elements  necessary  for  producing  good  crops.''' 

Acids  and  Bases. — The  mineral  elements  that  make  up  the  a.^^h 
of  plants  are  not  present  in  the  free  state  but  in  various  combi- 
nations, as  acids  and  bases.  The  acids  and  ba.ses  of  the  mineral 
elements  of  ash  are : 


'  Jordan.  The  Feeding  of  Aiii 


Ff:RTiLrrv  and  fertilizer  hints 


Sulphuric  (hydrogen,  sulphur  and  oxygen")  H-.SO^ 
Hydrochloric  (hydrogen  and  chlorinej  HCl 
Phosphoric  (hydrogen,  phosphorus  and  oxygen)  H,,P._,Os 
Carbonic  (carbon  and  oxygen)  CO. 
Silicic  (silicon  and  oxygen)  SiO., 

Bases 

Lime  (calcium  and  oxygen)  CaO 
Soda  (sodium  and  oxygen)   XajO 
Potash  (potassium  and  oxygen)  K^O 
Magnesia  (magnesium  and  oxygen)  MgO 
Iron  oxide  (iron  and  oxygen)  Fe^O;. 
The  mineral  elements  do  not  exist  as  acids  and  bases  in  the 
ash  because   in  the  burning  of  plant   substances  there   is  a   re- 
arrangement of  the  mineral  elements  and  salts  are   formed. 

Salts. — The  elements  exist  in  the  ash  of  plants  as  salts.     That 
is  the  acids  and  bases  are  united  and  form : 
Phosphates      ]  |     Calcium 

Sulphates         |^  '      Magnesium 

Chlorides         f  ^     Sodium 


Carbonates      j  [     Potassium 

We  are  all  familiar  with  some  of  these  salts 
combinations   are : 
Chloride  of  sodium  (conmion  salt) 
Carbonate  of  lime  (limestone) 
Chloride  of  potash  (muriate  of  potash ) 
Carbonate  of  soda   (baking  powder) 


A  few  of  the 


Sulphate  of  soda  (Glauber's salts) 
Sulphate  of  magnesia  (Epsom  salts) 
Sulphate  of  calcium  (gypsum) 
vSulphate   of   potash   (common   sul- 
phate of  potash  of  commerce) 

Variation  of  Ash. — The  content  of  ash  in  diiTerent  plants  and 
parts  of  plants  varies  a  great  deal  as  the  following  table  shows : 


Corn  .  • 
Oats  .. 
Rice  .. 

Wheat 


Roots  and  tubers  (fresli) 


Beet  (mangel; 

Carrot 

Irish  potato- 
Sweet  potato- 


Ash 
Per  cent. 

1-5 

3.0       ! 
5-5 
1.8 

i.o        1 

t       1.0        ^ 

Oat 

Rice 

Rve 

Wheal 

Forage  plants  (hay) 

Alfalfa 

Crimson  clover 

i  Orchard  grass 

Timothv 


Ash 
Per  cent. 


5-1 
7.8 
3-2 
4-2 


7-4 
8.6 
6.0 
4-4 


:M1CAL   KUiMI'.NT: 


XlvK 


r.V    TLA  NT: 


Different  parts  of  the  same  plant  vary  in  ash  content. 


Ash 
Per  cent. 


Ash 
Per  cent. 


Corn  grain 1.5 

Corn  leaves \  9.7 

Corn  (whole  plant) 4.3 

Corn  germ 1  4.0 


Corn  stover  (whole  plant  ex- 
cept ears)    4.9 

Corn  shucks 3.4 

Corncob 1.4 

Corn  bran 1.3 


There  is  also  a  variation  in  the  amounts  of  compoimds  in  the 
ash  of  different  parts  of  the  same  plant.  The  percentages  of 
the  compounds  in  this  table  are  figured  on  100  per  cent,  ash  of 
sugar-cane.^ 


Ash  of 

leaves 

Per  cent. 


Ash  of 

stalk 

Per  cent. 


Ash  of 

roots 

Per  cent. 


Potash  

Soda 

Lime 

Magnesia 

Iron  oxide 

Alumina 

Silica 

Phosphoric  acid 
Sulphuric  acid-  • 
Carbonic  acid  ■ . 

Chlorine 

Carbon   

Ash 


31-25 
1. 17 
590 
5.11 
1-45 
1.03 

30.32 
7-25 

11.29 

I. ID 
3.08 
0.16 
2.23 


38  23 
1.30 

5-19 
5.76 
I-I3 
0.25 

15.70 
5-27 

18.47 
2.70 
4-52 
0.54 
0.64 


17-39 
085 

3-45 
2.61 
3.60 
4.70 
49-52 
3-99 
9-15 
0.45 
0.98 
2  30 
1.87 


From  the  figures  given  in  the  foregoing  tables  we  find  that 
the  leaves  of  plants  contain  the  most  ash.  The  straws  contain 
more  ash  than  the  grains. 

Let  us  see  the  relation  of  the  ash  of  roots  to  the  leaves  of 
the  same  plant. 


Roots 

Per  cent. 

Ash 

Leaves 
Per  cent 

Ash 

3-83 

14. 8S 

8.01 

.1.64 

Sugar-beet 

Stock  turnip 

The   per  cent,   of  ash   in   seeds   is  generally  less   than   in   the 
plant  from  which  they  are  derived. "*' 

'  Hill,  gi,  I.onisiaiia  Kxperiment  Station. 


FliRTILlTY    AND   FERTIUZER    HINTS 


Ash 
Per  cent. 

Ash 
Per  cent. 

O           V»                       A 

2.1 
3-2 

47 

4.6 

7-5 

7  2 

Occurrence  of  Mineral  Elements  in  Plants. — According  to 
P'orbes  ;^  Mineral  substances  of  foodstuffs  are  present  in  four 
mechanical  conditions:  i.  In  solution  in  the  plant  juices;  2.  as 
crystals  in  the  tissues;  3.  as  incrustations  in  cells  and  4.  in 
chemical  combination  with  the  living  substance. 

The  mineral  content  of  any  species  of  plant  varies  consider- 
ably as  affected  (i)  by  the  composition  of  the  soil  and  the  soil 
water,  (2)  by  the  various  factors  controlling  transpiration  of 
water  by  the  plant  and  (3)  by  the  loss  of  mineral  substance 
either  through  shedding  of  parts  or  through  the  leaching  effect 
of  dews  and  rains. 

Distribution  of  Ash  in  Plants. — Roots  and  seeds  generally  con- 
tain much  less  ash  than  leaves  because  the  mineral  elements  are 
carried  to  the  leaves  for  the  elaboration  (manufacturing)  of 
food  and  then  the  water  evaporates  and  the  ash  remains.  The 
ash  present  in  roots  and  seeds  is  usually  needed  for  supporting 
germination  and  early  growth  of  the  plant,  while  some  of  that 
in  the  leaves  is  in  excess  of  what  is  really  needed. 

Phosphorus  and  potassium  are  present  in  the  largest  amounts 
in  seeds,  followed  by  magnesia.  Silicon  and  potassium  pre- 
dominate in  cereal  grasses  and  straws,  and  the  per  cent,  of  cal- 
cium is  usually  larger  than  phosphorus  or  magnesium.  The 
leguminous  crops  (alfalfa,  clovers,  cowpeas,  soy  beans,  etc.)  con- 
tain more  calcium  than  phosphorus  or  potassium.  Roots  and 
legumes  contain  much  less  silicon  than  straws. 

Ash  of  Young  and  Mature  Plants. — According  to  Wolfif  the  per 
cent,  of  ash  of  the  dry  matter  of  wheat,  oats,  rye,  and  clover 
decreases  with  the  growth  of  the  plant.  The  ash  of  healthful 
plants  is  generally  higher  in  calcium  than  in  sickly  plants.  The 
per  cent,  of  calcium  and  potassium  in  the  ash  of  grass  plants 
decreases  in  the  growing  of  the  plant  and  the  silicon  increases. 
In  the  ash  of  the  dry  matter  of  clover,  the  magnesium  and  cal- 
cium increase  while  the  potassium  decreases. 

1  Bui.  201.  Ohio  Experiment  Station. 


CHAPTER  II. 

THE  FERTILITY  OF  THE  SOIL. 

The  fertility  of  the  soil  is  shown  in  the  crops  produced  and  a 
soil  is  said  to  be  fertile  when  profitable  crops  are  grown  under 
favorable  conditions. 

Composition  of  Soils. — In  order  to  understand  the  conditions 
which  affect  fertility  let  us  become  familiar  with  the  composi- 
tion of  soils.  Soils  are  made  up  of  disintegrated  (ground) 
rocks  and  decayed  plant  and  animal  life.  Some  soils,  like  sandy 
soils,  predominate  in  rock  particles  while  peaty  soils  are  rich 
in  decayed  plant  material.  Most  soils  contain  both  ground  rocks 
and   decayed  plants. 

Inorganic  Matter. — That  part  of  the  soil  composed  of  ground 
rocks  (sand,  silt,  clay,  etc.)  is  called  inorganic  matter  and 
corresponds  to  some  extent  to  the  ash,  or  non-combustible,  or  in- 
organic matter  in  plants.  Of  course  the  particles  of  inorganic  mat- 
ter in  the  soil  may  be  different  from  the  original  rocks  from  which 
they  were  derived,  due  to  the  action  of  rain,  frost,  sun,  etc.,  yet 
we  find  that  a  considerable  portion  of  these  particles  is  often  of 
the  same  composition  as  the  original  rocks. 

Organic  Matter. — The  decaying  vegetable  or  animal  matter  in 
the  soil  is  called  organic  matter.  It  is  that  part  of  the  soil 
which  is  driven  off  when  burned  and  corresponds  to  the  organic 
matter  in  plants.  Most  of  the  organic  matter  in  soils  comes 
from  decaying  vegetation.  When  this  decaying  vegetable  or  animal 
matter  becomes  thoroughly  decomposed  it  assumes  a  black  waxy 
consistency  and  is  called  humus.  This  humus  is  a  very  im- 
portant constituent  and  influences  to  a  great  extent  the  physical 
and  biological  condition  of  soils. 

The  amount  of  organic  matter  in  soil  influences  its  water  hold- 
ing capacity,  texture,  temperature,  color,  supply  of  available 
plant  food  and  general  productiveness. 

Factors  Influencing  Soil  Fertility. — There  are  many  factors  in- 
fluencing soil  fertility  and  these  may  be  summed  up  under  the 
following  heads : 


14 


Fl-KTILITV    AND   I'lvRTlLI/.l'K    HINTS 


1.  The  available  supply  of  plant  food. 

2.  The  physical  condition  of  the  soil. 

3.  The  biological  condition  of  the  soil. 

I.  The  Plant  Food  Supply. — It  may  be  surprising  to  know  that 
most  farm  soils,  even  those  that  produce  poor  crops,  are  abund- 
antly supplied  with  plant  food.* 

Chester  of  the  Delaware  Agricultural  College,  states:^  An 
average  of  the  results  of  49  analyses  of  the  typical  soils  of 
the  United  States  showed  per  acre  for  the  first  eight  inches  of 
surface,  2,600  pounds  of  nitrogen,  4.800  pounds  of  phosphoric 
acid  and  13,400  pounds  of  potash.  The  average  yield  of  wheat 
in  the  United  States  is   14  bushels  per  acre.     Such  a  crop  will 


Plant  Food  Removed  by  Crops  in  Pounds  Per  Acre. 


Crop 


Wheat,  20  bu 

Straw 

Total 

Barley,  40  bu  ■  •  •  ■ 
Straw 

Total 

Oats,  50  bu 

Straw 

Total 

Corn,  65  bu 

Stalks  

Total 

Peas,  30  bu 

Straw 

Total 

Flax,  15  bu 

Straw 

Total 

Meadow  hay  . . . . 
Red  clover  hay  •  • 
Potatoes,  300  bu. 
Mangels,  10  tons 


WeTght       >^J'-S^" 


1,200 

2,OCO 


1,920 
3.000 


1,600 
3,000 


2,200 
6,000 


1,800 
3.500 


2,000 

4,oco 
18,000 
20,000 


25 


900  I   39 
1,800     15 


Phosphoric      p^^^^j^ 


12-5 

7-5 


9 

1-5 

9-5 


Bowker,  Plant  Food. 

Bui.  47,  Minnesota  Experiment  Station. 


TlIK    FKRTILITV    OF    TIIK    SOU.  1 5 

remove  29.7  poiuuls  of  nitrogen,  y.5  puuiuls  of  i)hi)>i)lu)ric  acid 
and  13.7  pounds  of  potash.  Now  if  all  the  potential  nitrogen, 
phosphoric  acid  and  potash  could  be  rendered  available,  there 
is  present  in  such  an  average  soil,  in  the  tirst  eight  inches, 
enough  nitrogen  to  last  90  years,  enough  phosphoric  acid  for 
500  years  and  enough  potash  for  1,000  years. 

Let  us  find  out  the  amounts  of  nitrogen,  phosphoric  acid, 
potash  and  lime  removed  per  acre  by  some  of  our  leading  farm 
crops. 

From  these  figures  it  is  evident  that  all  of  the  above  soils 
have  sutiticient  amounts  of  plant  food  to  last  for  many  years. 
Corn  yielding  65  bushels  per  acre,  only  takes  away  85  pounds 
of  nitrogen,  32  pounds  of  phosphoric  acid  and  95  pounds  of 
potash.  Mangels  which  are  heavy  users  of  potash  only  show  a 
removal  of  150  pounds  for  a  ten  ton  crop.  When  we  compare 
the  amounts  of  these  constituents  removed  by  crops  and  the 
total  supply  in  the  average  soil  we  may  better  realize  the  amount 
of  stored  up  plant  food  in  soils.* 

Plant  Food  not  Available. — The  question  naturally  arises,  what 
is  the  use  of  adding  fertilizers  or  manure  to  soils  when  such 
large  amounts  of  plant  food  are  present?  The  plant  food  in 
the  soil  is  dormant ;  it  is  locked  up  ;  it  is  unavailable.  Available 
plant  food  may  be  present  but  the  condition  of  the  soil  may 
be  such  that  the  plant  cannot  utilize  it.  The  soil  may  be  acid  or 
sour,  or  it  may  contain  olijcctionable  substances  distasteful  to 
plants. 

The  plant  obtains  its  nourishment  from  the  salts  in  solution 
in  the  soil  water  and  these  soluble  salts  constitute  the  available 
plant  food.  The  chemist  can  determine  the  total  plant  food,  or 
the  potential  fertility,  in  the  soil,  but  he  cannot  tell  us  how 
rriuch  is  available.  The  available  plant  food  supply  may  l)c 
ascertained,  to  a  certain  extent,  by  carrying  on  field  experiments. 
The  results  of  such  experiments  will  of  course  vary  with  differ- 
ent soils  and  different  crops.  The  chemist  can  determine  whether 
a  soil  is  acid,  alkaline  or  neutral  and  from  such  data  advise 
whether  lime  would  benefit  the  soil,  the  amoimt  to  apply  and  the 
kind  of  fertilizers  to  use.     In  such  cases  a  chemical  aualvsis  is 


l6  FE;R'riUTY   AND   FERTILIZER    HINTS 

exceedingly  valuable  but  ordinarily  field  trials  with  crops  prove 
the  better  way  of  determining  productiveness. 

The  Essential  Elements. — In  the  preceding  chapter  the  elements 
needed  by  plants  were  discussed  and  the  composition  of  plants 
given.  From  the  composition  of  plants  aided  by  field  experi- 
ments it  has  been  possible  to  learn  that  certain  elements  are 
necessary  for  plant  growth.  From  this  data  it  has  been  ascer- 
tained that  only  three  and  sometimes  four  elements  are  required 
to  be  furnished  the  plant  for  its  complete  development,  as  the 
other  elements  are  fortunately  present  in  sufficient  quantities  in 
the  air  and  the  soil  so  that  we  do  not  consider  them.  Nitrogen, 
(N)  phosphorus  (phosphoric  acid,  PioO-,)  and  potassium  (potash. 
K2O)  are  the  elements  usually  exhausted  most  readily  from 
the  soil,  and  occasionally  calcium  (lime,  CaO).  Because  of  the 
necessity  of  adding  nitrogen,  phosphoric  acid  and  potash  for  the 
growth  of  most  crops,  the  name  "essential"  is  applied  to  these 
elements,  and  the  remaining  elements  are  termed  ''unessential." 
The  essential  elements,  nitrogen,  phosphoric  acid  and  potash  are 
usually  found  in  larger  amounts  in  plants  and  in  smaller  quanti- 
ties in  soils  than  the  other  elements.  Nitrogen  and  phosphoric 
acid  are  usually  more  Hable  to  be  deficient  than  potash,  and  lime 
is  only  occasionally  lacking.  The  term  fertilizers  is  applied  to 
materials  containing  any  or  all  of  these  essential  elements,  in 
available  form,  and  are  supposed  to  make  up  for  the  deficiencies 
in  the  soil.  Fertilizers  may  contain  other  elements  as  magnesia, 
sulphuric  acid,  etc.,  though  needed  by  the  plant  are  unessential  as 
the  soil  contains  a  sufficient  amount  for  crops. 

The  fifteen  elements  used  by  plants  may  be  classified  as: 
Elements  sometimes  lack-    Elements  obtained  from    Elements  that  are  pres- 
in  the  soil  the  air  or  water  ent   usually   in  suffi- 

cient amounts 
Nitrogen  Hydrogen  Calcium  (usually) 

Phosphorus  Oxygen  Iron 

Potassium  Carbon  Sulphur 

Calcium  (occasionally)        Nitrogen  (sometimes)       Magnesium 

Silicon 
Sodium 
Chlorine 
Manganese 
Aluminium 


TIIIC    I-ERriLITV    Ol-    THE    SOIL 


17 


One  Element  Cannot  Replace  Another. — It  must  be  understood 
that  no  one  of  these  essential  elements  can  take  the  place  of 
another,  as  each  has  its  particular  functions  to  perform  which 
are  different  for  each  element.  Therefore  should  a  soil  be  de- 
ficient in  any  of  these  essential  elements,  the  addition  of  those 
that  are  lacking  will  tend  to  produce  good  crops,  provided  other 
conditions  are  favorable.     Let  us  illustrate  this  by  supposing  we 


I-'ig-  2.— I,  Unfertilized;  2.  Potash,  phos.  acid,  nitrogen;  3,  phos.  acid,  nitrogen. 
Courtesy  German  Kali  Works. 

wish  to  plant  a  field  of  corn.  We  have  perhaps  plenty  of  avail- 
able phosphoric  acid,  potash  and  lime  for  the  needs  of  the  corn 
and  the  land  is  in  good  condition,  but  the  available  supply  of 
nitrogen  is  deficient  in  the  soil.  We  cannot  grow  a  profitable 
crop  of  corn  under  such  conditions  because  the  phosphoric  acid, 
potash  and  the  lime  are  unable  to  take  the  place  of  the  nitrogen, 
no  matter  how  abundant  they  may  be.  Should  nitrogen  be  sup- 
plied in  sufficient  amount  the  crop  would  be  satisfied  and  should 
prove  profitable,  other  conditions  being  right. 


l8  l-EKTILITV    AND   FKRTILIZKR    IIIXTS 

It  has  been  found  that  sodium  and  potassium  may  replace 
each  other,  to  a  Hmited  extent,  in  correcting  the  acidity  that  may 
take  place  in  plants,  although  they  cannot  replace  each  other 
in  supplying  plant  food.  There  are  some  elements  which  have 
common  functions,  but  each  element  has  its  work  to  perform  for 
the  complete  development  of  plants. 

2.  Physical  Condition  of  the  Soil. — There  are  some  soils  which 
contain  sufficient  amounts  of  available  plant  food  for  the  needs 
of  crops  but  this  food  cannot  be  utilized  because  of  other  fac- 
tors Avhich  affect  the  physical  condition  of  soils.  Some  of  these 
factors  will  be  briefly  discussed. 

Temperature. — The  temperature  of  the  soil  depends  upon  the 
heat  of  the  air  and  the  nature  of  the  soil.  It  is  a  very  important 
consideration  in  plant  growth.*  In  summer  the  sunshine  causes 
the  upper  soil  to  be  warmer  than  the  lower  or  deeper  soil.  In 
winter  the  deeper  soil  is  warmer  than  the  surface  soil.  In  other 
words  the  temperature  of  the  air  affects  soil  warmth. 

The  germination  of  seed,  the  transference  of  soil  water,  which 
contains  the  available  plant  food,  the  movement  of  the  soil  air, 
the  development  of  organisms  are  all  greater  when  the  soil  is 
warm.  The  coarser  soils  seem  to  warm  up  more  readily  than 
the  heavy  clays.  The  location  of  the  land  influences  soil  warmth. 
A  soil  with  a  southern  exposure  is  naturally  warmer  than  one 
with  a  northern  location.* 

Mechanical  Composition.— Should  we  examine  a  few  different 
soils  we  would  find  that  there  is  a  great  difference  in  the  size 
of  the  particles  or  grains  that  make  them  up.  For  example, 
when  lumps  of  dift'erent  soils  are  broken  up  and  passed  through 
sieves  of  various  sizes,  or  shaken  in  bottles  with  water,  parti- 
cles varying  in  size  from  gravel  to  fine  dust  are  apparent.  The 
grains  or  particles  of  soil  are  usually  classified  into  four  groups : 
gravel,  sand,  silt  and  clay.  Sandy  soils  predominate  in  the  larg- 
est particles,  gravel  and  sand ;  alluvial  or  silt  soils  contain  more 
particles  the  size  of  silt,  and  clay  soils  have  more  of  the  finest 
particles,  clay.  It  should  be  understood  that  all  soils  contain 
large  and  small  particles.  A  loam  soil  contains  all  the  particles 
in  about  equal  proportions.* 


TiiK  I'KKriLnv  OF  Tin-;  son.  19 

The  percentages  of  moisture,  humus  and  carbonate  of  hme 
are  not  inckided  in  the  mechanical  analyses  of  soils. 

Surface  Area  of  Soil  Grains. — The  surface  area  of  soil  trains 
varies  with  the  size  of  the  particles.  The  smaller  the  grains 
the  more  surface  area  is  exposed  to  the  action  of  water  and  soil 
organisms,  and  the  more  quickly  is  plant  food  rendered  available. '■' 

Diameter  of  grain.  Square  feet  of  siirface  in  a  pound. 

Coarse  sand  i  mm. 11 .05 

Fine  sand,  o.  i  mm. 1 10.54 

Silt,  o.oi  mm.  1,105.38 

Clay,  o. 001  mm.  11,053.81 

_Fine  clay,  o.oooi  nmi   i,  100,538.16 

Lumpy  Soils. — The  mechanical  composition  of  a  soil  is  import- 
ant, for  the  farmer  to  consider,  in  order  to  keep  the  soil  re- 
ceptive for  growing  crops.  The  clustering  or  lumping  of  soils 
is  brought  about  by  the  adhering  of  the  particles  due  to  the  sur- 
face tension  of  the  films  of  water  surrounding  the  grains.  As 
the  water  dries  out  the  grains  are  held  together  with  the  aid  of 
the  salts  in  solution.  Fine  soils,  like  clay,  contain  manv  more 
particles  than  sandy  soils,  so  it  is  apparent  that  clay  soils  are 
more  apt  to  form  lumps  than  the  coarser  soils. 

Cracking  of  Soils. — When  soils  become  dry  the  films  of  water 
around  the  soil  particles  become  thinner  and  the  soil  contracts, 
breaking  in  the  weakest  point,  causing  cracks. 

Puddling  of  Soils. — If  soils  are  worked  when  in  a  very  wet 
condition  the  soil  particles  run  together  and  a  puddling  soil  is 
formed.  After  such  a  soil,  especially  a  clay  soil,  dries  out  it 
becames  very  hard  and  most  difficult  to  restore  to  good  condition. 
A  farmer  should  never  work  a  clay  soil  when  it  is  too  n-et. 

Freezing  and  Thawing. — When  soils  are  plowed  deepl>'  in  the 
fall  and  allowed  to  be  acted  upon  by  the  frosts  a  helpful  crumb 
like  condition  results.  The  action  of  frosts  is  more  ap])arent 
when  northern  and  .southern  soils  are  compared.  The  northern 
soils  treated  as  above  are  usually  in  better  tilth  than  the  south- 
ern soils  in  sections  of  little  or  no  frost. 

Plants  are  Benefited  by  Open  Soils. — A  good  tilth  of  the  soil 
helps  the  plant  a  great  deal  in  securing  its  food,  and  is  therefore 
an  important  factor  in  the  production  of  crops.     A   soil  should 


20  FERTILITY   AND   FERTILIZER    HINTS 

be  compact  enough  to  support  the  plant  in  an  upright  position, 
but  if  it  is  too  compact  the  young  plant  has  to  overcome  a  great 
deal  of  resistance  in  securing  its  food. 

Plants  Must  Have  Room. — Only  a  certain  number  of  plants  can 
be  grown  successfully  on  a  given  space  of  land.  We  have  only 
to  examine  the  root  development  of  mature  plants  to  learn  the 
spreading  tendency  of  plants.  If  plants  are  too  crowded,  im- 
perfect development  is  the  result.  The  roots  of  plants  spread 
somewhat  and  the  distance  apart  is  regulated  to  some  extent  by 
the  available  plant  food,  the  nature  of  the  plant  and  the  tillage 
of  the  soil.  In  the  foreign  countries  more  plants  are  usually 
grown  on  a  given  area  than  in  America  but  the  land  is  perhaps 
more  thoroughly  tilled,  because  land  is  high  in  price  and  labor 
cheap,  while  in  America  land  is  comparatively  cheap  and  labor 
high.  In  w-ell  tilled  soils  roots  go  deeper  and  do  not  spread  so 
much  as  in   soils  in  poor  condition. 

Plants  Require  Oxygen. — A  soil  that  is  too  compact  will  not  per- 
mit of  the  free  circulation  of  air.  When  air  is  excluded  from 
the  soil,  free  oxygen  which  is  absolutely  necessary  for  growth 
is  excluded.  It  has  been  shown  that  when  air  is  not  freely  sup- 
plied to  plants  they  become  sickly  and  growth  is  retarded.  When 
a  soil  becomes  water-logged,  plants  w^ill  not  grow  and  if  the 
condition  continues  the  plants  will  die.  Some  plants  will  grow 
in  water  but  the  water  must  be  fairly  free  from  soil  so  as  to  be 
able  to  absorb  and  diffuse  oxygen  from  the  air.  It  has  been 
found  that  40  to  60  per  cent,  of  the  water  holding  capacity  of 
soils  is  the  best  amount  and  80  per  cent,  is  injurious. 

Drainage. — Good  crops  cannot  be  grown  unless  the  land  is  well 
drained,  either  naturally  or  artificially.  A  certain  amount  of 
water  is  essential  for  crops,  but  a  water-logged  condition  must 
be  avoided  to  secure  good  results. 

Capillary  Water. — In  the  preceding  chapter  we  learned  that 
crops  use  a  great  deal  of  water,  the  clover  crop  for  example 
exhales  as  much  as  1,096,234  pounds  per  acre.  Crops  usually 
rely  on  capillary  water  for  their  supply  of  this  constituent.  The 
upward  movement  of  water  in  the  soil  is  termed  capillary 
inoisture,  or  capillary  water,  and  is  caused  by  the  surface  ten- 


THE    FERTILITY    OF    THE    SOIL  21 

sion  of  the  films  of  water  around  the  soil  particles  heconiing 
greater  as  evaporation  from  the  upper  surface  of  the  soil  takes 
place.  One  of  the  most  important  problems  in  farming  is  to 
conserve  this  soil  moisture  and  prevent  its  evaporation. 

Amounts  of  Capillary  Water  Held  by  Soils. — Sandy  soils  hold 
very  little  capillary  water.  After  a  rain  it  is  estimated  that  5 
to  10  per  cent,  by  weight  of  the  soil  will  be  water.  Sandy 
loams  and  silt  loams  retain  15  to  20  per  cent,  and  heavy  clay 
soils  30  to  50  per  cent.  Heavy  clay  soils  are  suitable  for  grass 
lands  because  of  this  power  of  holding  water,  as  grasses  re- 
quire considerable  water  for  maximum  growth. 

How  to  Prevent  Loss  of  Capillary  Water. — As  capillary  water  is 
so  important  for  the  welfare  of  crops  we  should  learn  how  to 
prevent  its  loss.  Water  will  follow  along  the  path  of  least 
resistance.  So  if  we  form  a  soil  mulch  by  cultivating  or  stirring 
the  soil  to  the  depth  of  two  or  three  inches  we  will  ofifer  re- 
sistance to  the  upward  movement  of  water.  The  soil  should  not 
be  cultivated  too  deeply  because  some  of  the  small  roots  are  lia- 
ble to  be  injured. 

How  to  Increase  the  Upward  Movement  of  Capillary  Moisture. — 
When  seeds  are  planted  in  dry  seasons  it  is  often  advisable  to  bring 
up  the  water  to  aid  in  their  germination.  This  may  be  ac- 
complished by  rolling  the  soil  thus  making  it  firmer.  After 
rolling  it  is  important  to  form  a  soil  mulch  again  to  prevent  the 
loss  of  all  the  water.* 

3.  The  Biological  Condition  of  the  Soil. — All  cultivated  produc- 
tive soils  are  full  of  organisms,  both  animal  and  vegetable,  which 
aid  in  furnishing  plant  food.  There  are  many  different  organ- 
isms whose  functions  vary  a  great  deal.  Most  of  these  organ- 
isms are  so  small  that  they  cannot  be  seen  without  the  aid  of 
the  microscope,  while  some,  with  which  we  are  all  familiar, 
are   large. 

The  rodents,  worms  and  insects  all  have  their  place  in  stirring 
the  soil  although  the  rodents  and  some  of  the  insects  are  in- 
jurious to  crops.  Plant  roots  are  beneficial  in  that  they  leave 
organic  matter  in  the  soil  and  openings  for  the  access  of  water 
and  air. 


22  FERTILITY    AXD    FERTILIZER    PIIXTS 

The  organisms  we  are  most  interested  in  are  the  bacteria 
(minnte  plants)  because  of  their  beneficial  effect  in  crop  jiro- 
duction. 

The  number  of  bacteria  in  the  soil  depends  upon  its  physical 
condition.  Water-logged  soils,  sandy  soils,  acid  soils,  and  soils 
low  in  organic  matter  contain  very  few  and  sometimes  no  bac- 
teria. Soils  rich  in  humus,  contain  sometimes  as  high  as  loo,- 
000,000  bacteria  per  gram,^  while  the  average  well  cultivated  soil 
contains  1,000,000  to  5,000,000  per  gram.  The  cold  winters 
of  the  north  decrease  the  number  of  bacteria  but  these  multiply 
during  spring  and  summer.'^' 

Nitrification. — Certain  bacteria  have  the  power  of  converting 
the  organic  nitrogen  present  in  animal  and  vegetable  matter  into 
ammonia.  No  doubt  you  are  all  familiar  with  the  ammonia 
smell  around  fermenting  manure.  This  is  the  result  of  the  action 
of  bacteria.  The  same  action  that  takes  place  in  the  manure 
heap  occurs  in  the  soil  when  organic  matter  is  present.  W'hen 
the  ammonia  is  formed  another  kind  of  bacteria  seizes  it  and 
changes  the  ammonia  into  nitrous  acid  or  nitrites,  and  this  latter 
compound  is  in  turn  attacked  by  another  organism  and  con- 
verted into  nitric  acid  or  nitrates.  In  this  latter  form  it  is  readi- 
ly dissolved  by  the  soil  water  and  available  as  plant  food.  There 
is  a  continual  cycle  of  the  forms  of  nitrogen.  The  plant  uses 
the  nitrogen  in  the  form  of  nitrates,  converts  it  into  organic 
nitrogen,  and  wdien  the  plant  dies  it  may  be  returned  t(^  the  soil 
to  go  through  the  same  process  again. 

Manure  or  other  organic  matter  helps  nitrification. ^'^  Keeping 
the  soil  well  open  so  that  a  liberal  supply  of  air  may  ]:)ermeate  it 
has  a  beneficial  effect  on  nitrification.  The  more  porous  the  soil 
the  deeper  nitrification  occurs. 

Denitrification. — There  are  some  bacteria  that  set  free  nitrogen. 
These  bacteria  exert  a  reducing  action  rather  than  an  oxidizing 
one.  Some  reduce  nitrates  (nitric  acid)  to  nitrites  C nitrous  oxide) 
and  ammonia.  Others  reduce  nitrates  to  nitrites  and  then  to 
free  gaseous  nitrogen.     It  has  been   found  that   there  arc  more 

1  One  ounce     --  28.35  grams. 


THK    I'KR'nLlTV    01<    THE    SOIL  23 

denitrifying  organisms  than  nitrifying  bacteria,  although  the  loss 
of  nitrogen  from  well  drained  and  tilled  soils  is  not  large, 
because  the  denitrifying  bacteria  cannot  attack  the  nitrogen  in 
such  soils.  The  nitrogen  wasting  bacteria  work  considerable 
damage  in  manure  heaps. 

Organisms  that  Gather  Nitrogen. — Other  organisms  found  in  the 
soil  that  exert  an  effect  on  its  fertility  are  those  that  live  in 
the  tubercles  or  nodules  on  the  roots  of  certain  plants  called 
the  legumes,  of  which  cowpea,  bean,  pea,  clovers,  alfalfa,  vetch, 
etc.,  are  examples.  These  plants  through  the  action  of  these 
bacteria,  have  the  power  of  accjuiring  the  free  gaseous  nitrogen 
from  the  air  and  utilizing  it  in  their  growth.  The  bacteria  se- 
cure this  free  nitrogen  from  the  air  in  the  soil  and  the  plant 
acquires  it  from  the  bacteria.  When  the  plant  dies  the  nitrogen 
left  in  the  roots  remains  in  the  soil  and  thus  enriches  it.  The 
particular  bacterium  can  only  attach  itself  to  the  legume  it  is 
suitable  to.  That  is,  bacteria  forming  tubercles  on  the  roots  of 
clover  will  not  grow  on  cowpea  roots.  When  there  is  a  plenti- 
ful supply  of  nitrogen  as  nitrates  in  the  soil  the  legumes  will 
not  always  form  tubercles  and  utilize  the  free  atmospheric  ni- 
trogen, but  will  gather  their  supply  from  the  soil.  Legumes 
therefore  are  able  to  secure  nitrogen  from  the  soil  and  the  air. 
The  tubercles  seem  to  form  better  in  alkaline  soils  containing 
lime. 

Inoculation  of  the  Soil. — The  absence  of  tubercles  on  the  roots 
of  legumes  may  therefore  be  due  to  the  absence  of  the  particu- 
lar bacteria  required,  to  the  excess  of  nitrates,  or  to  the  acidity 
of  the  soil.  Should  the  soil  be  deficient  in  the  particular  bac- 
teria needed,  the  soil  should  be  inoculated.  This  inoculation  is 
accomplished  by  sowing  soil  from  a  neighboring  field  that  has 
produced  a  good  crop  of  the  kind  desired,  or  if  such  a  soil  can- 
not be  obtained,  by  inoculating  the  seed  before  planting  with  a 
pure  culture  which  has  been  obtained  from  the  tubercles  of  the 
kind  of  crop  to  be  raised.  These  cultures  may  be  obtained  from 
the  United  States  Department  of  Agriculture  and  dealers  in  seeds. 
In  using  soil  from  another  field  for  inoculating,  fungus  diseases. 
3 


24  FERTILITY    AND   FERTILIZER    HINTS 

insects  and  objectionable  weeds  are  often  introduced  which  be- 
come a  serious  menace  in  the  production  of  crops.  Care  must  be 
taken  to  secure  soil  from  a  disease  free  field.  The  pure  cultures 
are  not  always  satisfactory,  as  they  are  hard  to  preserve  in 
transportation,  so  that  the  use  of  soil  is  perhaps  the  better  method 
just  now. 


CHAPTER  III. 


MAINTAINING  SOU  FERTILITY. 

As  the  fertilizer  ingredients  nitrogen,  phosphoric  acid  and 
potash  are  the  plant  food  elements  that  have  to  be  supplied,  let 
us  find  out  some  of  the  ways  they  are  taken  away  from  the  soil 
and  methods  of  preventing  and  restoring  their  loss. 

Erosion  is  the  loss  of  soil  by  the  action  of  water  or  wind. 

Any  one  who  has  ever  lived  in  the  South  is  familiar  with  the 
tremendous  losses  of  fertility  incurred  by  erosion.  The  most 
serious  losses  occur  on  hilly  clay  soils.  Cotton  and  corn  are 
grown  on  many  of  the  southern  soils  year  after  year  and  the 
soil  is  left  bare  during  the  winter.  These  soils  are  not  plowed 
very  deep  and  when  a  heavy  rain  comes  only  a  small  amount  of 
the  water  can  soak  into  the  soil.  If  the  land  is  hilly  the  rain 
forms  little  rills  at  first  which  finally  become  gullies  and  much 
of  the  good  fertile  soil  is  washed  to  the  valleys  or  bottom  lands. 
It  a  few  seasons  a  great  deal  of  such  hill  land  becomes  unpro- 
ductive. 

There  are  other  sections  in  America  besides  the  South  where 
erosion  is  damaging  farms.  In  some  of  the  far  western  states 
and  other  sections  where  the  land  is  hilly,  erosion  is  a  source  of 
loss  of  fertility. 

Erosion  by  water  besides  carrying  away  the  most  fertile  part 
of  the  soil  puts  the  land  in  such  a  condition  that  it  is  difficult 
to  operate.     Gullies  are  objectionable  in  growing  crops. 

On  light  sandy  soils  the  blowing  away  of  the  surface  soil  by 
wind  often  results  in  serious  losses  of  fertility.  Mounds  or 
ridges  are  often  formed  which  interfere  with  cultivating  the  soil. 

Ways  to  Check  Erosion. — Plowing  up  and  down  hill  is  very 
bad  practice  as  the  furrows  become  regular  waterways  during  a 
rain  storm.  In  the  South  the  lands  that  are  subject  to  erosion 
are  usually  the  clay  soils  which  will  not  absorb  water  readily. 
Shallow  plowing  is  practiced  and  deep  plowing  will  cause  more 
water  to  be  absorbed  and  retained.  Most  of  these  soils  are  lack- 
ing in  organic  matter.     By  growing  green  crops  in   the   winter 


26  FERTII^ITY    AND   FERTILIZER    HINTS 

and  turning  them  under  in  time  for  the  summer  crops,  erosion 
will  be  stopped  considerably  during  the  winter  and  much  organic 
matter  will  be  supplied  which  will  make  clay  soils  more  porous 
and  spongy.  Underdrainage  prevents  erosion  by  carrj'ing  the 
excess  of  water  away  gently. 

Many  farmers  terrace  their  soil  to  prevent  it  from  washing 
away.  This  custom  is  not  as  beneficial  as  deep  plowing,  plow- 
ing under  of  green  crops,  or  putting  the  land  in  pasture.  Many 
of  the  most  successful  farmers  keep  their  rows  level  so  when 
it  rains  the  water  remains  in  the  furrows  instead  of  washing 
down  hill.  These  furrows  will  not  be  straight  but  answer  the 
purpose  of  saving  fertility. 

Drainage, — The  loss  of  fertility  by  drainage  is  chiefly  concerned 
in  the  loss  of  nitrogen.  This  element  to  be  favorable  for  most 
plants  to  assimilate  must  be  in  the  form  of  nitrates  which  are 
readily  soluble  in  water.  Phosphoric  acid  and  potash  are  fixed 
in  the  soil  so  that  they  are  insoluble  in  water  and  hence  very 
inappreciable  amounts  are  lost  by  drainage.* 

Experiments  have  shown  that  the  loss  of  nitrogen  by  drain- 
age is  greater  on  soils  that  are  idle  than  on  cultivated  soils.  At 
first  thought  one  would  suppose  that  the  loss  would  be  greater 
on  the  cultivated  soils  as  they  are  more  open  and  porous,  and 
hence  permit  of  a  more  free  passage  of  water  through  the  soil. 

The  excess  of  nitrates  in  cultivated  soils  is  carried  down  in 
the  soil  but  after  a  rain  the  capillary  water  carries  it  up  again 
to  the  plant  roots.  Again,  the  plants  are  continually  using  up 
the  available  supply  of  nitrogen  as  fast  as  it  is  formed  so  that 
there  is  no  appreciable  excess  to  be  carried  away. 

It  has  been  found  that  about  37  pounds  of  nitrogen  per  acre 
are  lost  from  average  idle  land  during  a  year.  This  loss  of  ni- 
trogen is  quite  large  when  we  consider  that  20  bushels  of  wheat, 
not  counting  the  straw,  remove  25  pounds  of  nitrogen ;  50  bush- 
els of  oats,  35  pounds ;  and  65  bushels  of  corn,  40  pounds.* 

Fallowing. — In  the  arid  sections  of  this  country  where  dry 
farming  is  followed  it  is  often  necessary  to  let  the  land  remain 
idle  for  a  season  to  conserve  enough  moisture  to  produce  profit- 


MAINTAINING   SOIL   FERTILITY  2"] 

able  crops.  The  land  is  usually  plowed  two  or  three  times,  at 
intervals,  or  plowed  once  and  harrowed  two  or  three  times. 
This  procedure  keeps  down  the  weeds  and  increases  the  moisture 
in  the  soil.  According  to  King,  203  tons  more  water  was  found 
on  fallowed  land  per  acre  in  the  spring  following  the  fallow, 
than  on  land  that  was  not  fallowed,  and  179  tons  more  water 
was  found  on  the  fallowed  field  after  a  crop  was  harvested 
than  on  the  other  field. ^ 

Fallowing  increases  the  supply  of  available  nitrogen  as  ni- 
trates and  in  some  sections  fallowing  is  practiced  for  this  reason. 
The  yield  of  the  crop  following  fallowing  is  increased  but  con- 
siderable humus  is  lost  by  being  oxidized,  and  generally  more 
nitrates  are  formed  than  can  be  used  up  by  the  crop  following 
fallowing.  Snyder  has  found  by  experiments  that  590  pounds 
of  nitrogen  per  acre  were  lost  by  two  years  of  summer  fallow- 
ing, or  an  amount  sufficient  for  five  wheat  crops.-  At  the  Roth- 
amstead  Experiment  Station  experiments  show  that  considerable 
more  nitrogen  was  lost  from  bare  soils  than  from  wheat  land.* 

On  rich  soils  the  losses  are  greater  than  on  soils  deficient 
in  organic  matter  because  the  oxidation  of  humus  is  more  rapid. 
It  is  evident,  then,  that  fallowing  increases  the  production  of 
crops  at  the  expense  of  a  reduction  of  humus. 

In  sections  of  plentiful  rainfall,  fallowing  is  often  injurious 
and  it  should  only  be  practiced  in  the  dry  sections  where  there 
is  not  enough  rainfall  to  carry  away  the  nitrates  and  therefore 
not  sufficient  moisture  for  the  continuous  growing  of  crops. 

Other  Ways  Nitrogen  is  lost. — The  washing  away  of  nitrogen 
as  nitrates  is  not  the  only  way  this  element  is  lost,  but  con- 
siderable of  this  valuable  constituent  escapes  in  the  form  of  gases. 
This  loss  as  gas  is  occasioned  by  denitrification,  which  reduces 
the  nitrates  to  gases,  and  the  liberation  of  nitrogen  from  organic 
matter.  The  loss  on  soils  rich  in  organic  matter  is  greater  than 
on  poor  soils. 

Experiments  show  that  in  continuous  cropping  more  nitrogen 

'  Roberts,  The  Fertility  of  the  Soil 
-Snyder,  Soils  and  Fertilizers. 


28 


FERTILITY    AND   FERTILIZER    HINTS 


is  usually  lost  than  the  crop  removes.     The   following  table  il- 
lustrates this  point. ^ 
Loss  OF  Nitrogen  by  Continuous  Cropping  Per  Acre  Per  Year. 


Name  of  Crop. 


Nitrogen  removed 
by  crop. 
Pounds. 


Nitrogen  lost  by 

other  means. 

Pounds. 


Total  nitrogen  re- 
moved and  lost. 
Pounds. 


Wheat 
Corn . . 
Oats  . . 
Barley 


24-5 
56 
46 
30 


146.5 
29 
150 
170 


171 

85 
196 
200 


The  loss  of  nitrogen  by  continuous  cropping  of  cotton,  corn, 
tobacco  and  the  cereal  crops  is  a  very  serious  one. 

Loss  of  Phosphoric  Acid  and  Potash. — Although  phosphoric  acid 
and  potash  are  usually  present  in  the  soil  as  compounds  insolu- 
ble in  water,  nevertheless  large  quantities  are  lost  every  year 
by  being  carried  away  with  the  soil  into  rivers  and  other  streams. 
Again,  traces  of  phosphoric  acid  and  potash  are  carried  away  in 
the  soluble  form  by  drainage  and  although  this  loss  is  not  large 
per  acre  it  amounts  to  a  great  deal  in  the  course  of  time. 
The  Mississippi  River  deposits  in  the  Gulf  of  Mexico  3,702,- 
758,400  cubic  feet  of  solid  material  per  year.  One  cubic  foot 
of  this  solid  material  weighs  about  80  pounds.  This  material 
is  quite  rich  in  potash  often  containing  as  high  as  0.50  per  cent, 
of  this  constituent.  The  phosphoric  acid  content  is  much  lower 
than  this  figure  but  is  considerable.  The  rivers  that  empty 
into  the  oceans  in  the  northern  part  of  the  United  States  do  not 
perhaps  carry  away  so  much  fertility  as  the  rivers  of  the  far 
south,  but  the  annual  loss  of  the  mineral  elements  carried  away 
in  streams  is  appalling. 

One  Crop  Farming. — The  exclusive  growing  of  one  crop  caused 
more  farms  to  be  abandoned  in  the  United  States  than  any  other 
practice.  The  continuous  cropping  of  wheat  in  the  West,  to- 
bacco in  Kentucky,  Virginia  and  North  Carolina,  cotton  in  the 
South,  and  corn  in  the  North  Central  States  has  always  re- 
sulted in  the  loss  of  fertility  and  depletion  of  the  soil.  All  of 
these  crops  with  the  exception  of  corn  are  sold  from  the  farm 

1  Bui.  5'v  Minnesota  Experiment  Station. 


MAINTAINING   SOIL   FKRTILITV  29 

without  the  return  of  any  fertility.  On  most  of  these  one  crop 
farms  no  fertility  is  put  on  the  soil  and  the  farm  is  abandoned 
or  else  artificial  (commercial)  fertilizers  are  used.  Most  of  our 
soils  in  the  United  States  were  formerly  fertile  but  the  prac- 
tice of  growing  crops  without  returning  organic  matter  has  re- 
sulted in  decreasing  the  yields  on  our  older  cultivated  lands. 
Under  the  subject  "fallowing"  we  learned  that  it  was  poor  pro- 
cedure to  allow  the  land  to  lie  idle  except  in  dry  regions,  and 
the  best  farmers  to-day  are  those  that  utilize  their  land  con- 
tinually and  to  the  fullest  extent.  When  we  visit  some  of  the 
European  countries  where  land  has  been  in  cultivation  for  cen- 
turies,-we  find  that  these  lands  are  still  producing  valuable  crops, 
and  that  the  yields  are  as  large,  if  not  larger  now,  than  they  were 
two  centuries  ago.  This  condition  exists  in  Europe  because 
fertility  has  been  returned  to  the  soil  every  year  to  sustain  crops. 

Fortunately,  land  has  been  comparatively  cheap  in  the  United 
States  and  when  a  farm  failed  to  produce  paying  crops  another 
piece  of  land  was  secured,  and  so  on.  The  time  has  arrived 
when  the  acquiring  of  new  land  for  one  crop  farming  is  hard  to 
obtain  at  a  price  within  the  bounds  of  such  farmers.  So  it  is 
now  necessary  and  more  profitable  for  the  farmer  to  grow  other 
crops  in  conjunction  with  his  money  crop.  This  growing  of 
other  crops  is  called  diversifying  or  rotating. 

Diversification  and  Rotation  of  Crops. — Diversification  is  the 
growing  of  different  crops  without  any  regular  or  definite  sys- 
tem. Rotation  of  crops  is  spoken  of  as  growing  a  certain  num- 
ber of  crops,  in  regular  order,  on  the  same  piece  of  land.  For 
example,  a  rotation  may  consist  of  four  crops,  corn,  oats,  wheat 
and  clover,  and  will  be  called  a  four  year  rotation  because  these 
crops  will  be  grown  in  order  on  the  same  piece  of  land  and  take 
four  years  to  complete.  A  farmer  may  have  160  acres  in  his 
rotation, and  each  year  40  acres  will  be  allowed  for  each  of 
the  four  crops  mentioned.  Each  40  acres  will  grow  the  same 
crop  every  fifth  year  and  one  of  the  crops  every  year.  The 
terms  six-year,  five-year,  four-year,  three-year,  two-year,  etc., 
are  applied  to  rotations  depending  upon  the  time  it  takes  to 
complete  them.     Rotations  taking  15  years  to  complete  are  known 


30  FERTILITY    AND   FERTIUZER    HINTS 

in  Europe  but  the  short  rotations  of  three  to  six  years  are  found 
to  be  profitable  in  the  United  States. 

Make  up  of  a  Rotation, — The  crops  used  in  rotations  are  nat- 
urally selected  according  to  the  location,  nature  of  the  soil,  avail- 
able crops,  market  prices,  kind  of  farming-,  insect  and  plant  dis- 
eases, climate,  etc.  A  stock  farm  would  require  different  crops 
than  a  tobacco  farm ;  a  dairy  farm  in  Wisconsin  could  not  probably 
use  the  same  rotation  as  a  dairy  farm  in  Alabama ;  two  farms  in 
the  same  state  with  dift'erent  soil  conditions  would  perhaps  se- 
lect different  crops  for  a  rotation ;  a  farm  ten  miles  from  a 
market  would  no  doubt  find  it  more  practical  to  grow  different 
crops  than  one  i,ooo  miles  away;  and  crops  would  not  be  chosen 
that  insects  or  plant  diseases  ruin. 

Reasons  for  Rotating  Crops. — Some  of  the  reasons  for  rotating 
crops  are : 

1.  To   keep   down   weeds. 

2.  To  gather  nitrogen  from  the  air. 

3.  To  distribute  farm  labor  more  evenly. 

4.  To  eradicate  insect  or  other  diseases. 

5.  To  furnish  feed  for  live  stock. 

6.  To  give  the  farmer  a  regular  income. 

7.  To  prevent  losses   of   fertility. 

8.  To  utilize  plant   food  more  evenly. 

9.  To  include  deep  and  shallow  rooted  plants. 

10.  To  save  fertilizer  expenditure. 

11.  To  regulate  the  humus  supply. 

12.  To  conserve  moisture  in  dry  sections. 

I.  Rotation  of  Crops  Keeps  Down  Weeds. — It  is  well  known 
that  the  growing  of  particular  crops  is  accompanied  by  certain 
weeds.  Those  crops  that  are  sown  broadcast,  as  the  small  grains, 
are  more  apt  to  be  weedy  than  cultivated  crops  as  corn,  cotton, 
tobacco,  potatoes,  etc.  When  crops  like  wheat,  hay,  etc..  are 
grown  continuously  the  yields  or  the  quality  of  the  crops  are 
often  materially  reduced  by  weeds.  Intertilled  crops  as  corn,  to- 
bacco, cotton,  potatoes,  etc.,  when  well  cultivated,  are  known  as 
"cleaning  crops."     So  in   planning   a   rotation   crops   should   be 


MAINTAINING   SOIL   FERTILITY  3 1 

selected  that  will  tend  to  keep  down  weeds.     Cultivated  crops 
should  be  included  with  those  that  are  sown  broadcast. 

2.  Legumes  are  Profitable. — By  including  legumes  as  clovers, 
Canada  field  pea,  cowpea,  velvet  bean,  soy  bean,  etc.,  in  a  rotation, 
it  is  possible  to  gather  considerable  nitrogen,  which  is  the  most 
expensive  fertilizing  element  to  buy,  from  the  air.  A  crop  of 
red  clover,  one  year  old,  is  estimated  to  contain  20  to  30  pounds 
of  nitrogen  in  the  roots,  per  acre.  A  crop  of  cowpeas  in  Louis- 
iana furnishes  100  pounds  of  nitrogen  per  acre.  By  plowing 
under  leguminous  crops  enough  nitrogen  is  often  furnished  so 
that  the  following  crop  does  not  require  any  extra  supply,  and 
if  some  "nitrogen  has  to  be  supplied,  that  amount  is  much  less 
than  it  would  be  were  not  nitrogen  gathering  crops  utilized. 

The  Minnesota  Experiment  Station^  found  a  loss  of  2,000 
pounds  of  nitrogen  per  acre  when  wheat,  barley,  corn  and  oats 
were  grown  for  twelve  consecutive  years ;  two-thirds  to  three- 
fourths  of  this  amount  was  not  used  by  the  crops  but  was  lost 
in  other  ways.  The  Ohio  Experiment  station^  found  that  there 
was  a  gain  of  300  pounds  of  nitrogen  per  acre  in  excess  of  what 
the  crop  utilized  when  clover  was  included  in  five-year  rotations, 
covering  periods  of  ten  years.  When  timothy  and  non-legumes 
were  used  in  place  of  clover,  nitrogen  was  lost  from  the  soil ; 
the  loss  of  nitrogen  from  the  soil  was  a  little  more  than  that 
removed  by   the   crop. 

3.  The  Distribution  of  Farm  Labor. — One  of  the  most  important 
points  in  favor  of  a  rotation  of  crops  is  that  it  allows  of  a  more 
even  distribution  of  farm  labor.  When  several  crops  are  grown 
every  year  the  farmer  is  able  to  employ  help  the  greater  part 
of  the  year  and  thus  secure  more  efficient  labor  at  a  less  cost  for 
the  work  performed  than  should  single  crop  farming  be  in 
vogue. 

4.  The  Checking  or  Eradication  of  Insects  and  Plant  Diseases. — 
Many  times  crops  become  so  badly  attacked  by  insects,  or  in- 
fested with  plant  diseases,  that  there  are  no  profits  and  often 
large  losses   in  trying  to  produce  them  on  the   same  field  con- 

1  Bui.  89. 
'  Bui.  no. 


32 


FERTILITY    AND   FERTILIZER    HINTS 


tinually.  A  rotation  of  crops  often  eliminates  such  troubles  be- 
cause certain  insects  and  plant  diseases  are  only  common  to  one 
particular  crop.  A  good  illustration  of  this  is  noticeable  in  the 
growing  of  cotton.  There  is  an  insect  called  the  cotton  boll 
weevil,  which  punctures  cotton  bolls  and  destroys  the  crop. 
Fields  that  once  produced  valuable  crops  of  cotton  must  now 
be  planted  to  other  crops  which  are  not  injured  by  this  insect. 
5.  Rotation  Furnishes  Feed  for  Live-stock. — One  crop  farmers 
are  often  forced  to  buy  feed  for  their  live-stock.  A  farmer  who 
uses  a  rotation  of  crops  can  plan  his  rotation  so  that  most  of 
the    feed   will   always   be   produced   on   the   farm.     In  one  crop 


Fig.  3 — Oats  fit  well  in  rotations  and  furnish  feed  for  live-stock. 

farming  the  sale  of  the  crop  brings  only  one  value.  When 
several  crops  are  grown  it  is  possible  to  produce  feed  for  live- 
stock and  a  double  value  is  received  for  the  crop.  This  double 
value  is  represented  in  the  feeding  value  and  fertilizing 
value;  the  crop  is  fed  and  the  manure  spread  on  the  land. 

6.  A  Regular  Income. — Farmers  who  raise  single  crops  receive 
their  money  but  once  a  year  and  many  of  these   farmers  use 


MAINTAINING    SOIL    I'KRTILITV  33 

their  crops  in  paying  the  merchant  for  the  last  year's  supplies. 
They  often  live  from  year  to  year  on  the  credit  basis  and  pay 
much  more  for  their  supplies  than  the  farmer  who  is  able  to 
pay  for  what  he  gets  in  cash.  In  certain  sections  of  this  coun- 
try this  credit  system  of  farming  has  proved  disastrous  because 
one  or  two  bad  years  caused  the  loss  of  the  farm.  The  single- 
crop  farmer  generally  has  to  buy  more  supplies  than  the  farmer 
who  grows  several  crops.  The  farmer  who  practices  rotation 
has  crops  to  sell  at  different  times  in  the  year  and  so  has  a 
more  regular  income  than  the  single  crop  farmer  who  gets  his 
money  but  once  a  year. 

7.  Preventing  Losses  of  Fertility. — The  farmer  who  rotates  his 
crops  may  sell  the  crop  that  removes  the  least  fertility  from  the 
soil  and  if  the  money  crops  remove  a  great  deal  of  fertility, 
he  may  regulate  his  rotation  so  as  to  restore  this  loss  cheaply. 

8.  A  rotation  of  crops  utilizes  plant  food  more  evenly  than  when 
single  crops  are  continually  grown.  Corn,  wheat  and  other  grain 
crops  use  a  great  deal  of  nitrogen  and  phosphoric  acid  while 
tobacco  and  potatoes  are  heavy  potash  feeders.  By  the  proper 
selection  of  crops  forming  rotation,  the  plant  food  may  be  drawn 
on  more  evenly  and  losses  of  fertility  prevented  through  leach- 
ing, etc. 

9.  Deep  and  Shallow  Rooted  Plants. — A  rotation  of  crops  has 
an  advantage  over  single  crop  farming  because  of  the  variation 
in  depth  of  root  systems  of  different  crops.  Alfalfa  and  corn 
have  deep  tap  roots  and  obtain  food  from  the  subsoil,  while 
oats,  timothy,  blue  grass,  rye,  etc.,  have  shallow  roots  and  feed 
from  the  upper  soil.  By  alternating  deep  and  shallow  rooted 
plants  the  fertility  from  the  subsoil  and  surface  soil  is  more 
evenly  utilized.  Often  the  surface  soil  may  predominate  in  ni- 
trogen and  phosphoric  acid  and  the  subsoil  in  potash  and  lime. 
When  the  fertility  is  thus  distributed  the  alternating  of  shallow 
and  deep  rooted  plants  is  important  as  the  fertility  of  the  subsoil 
is  brought  to  the  surface  soil  by  the  decay  of  roots. 

Another  advantage  of  growing  deep  and  shallow  rooted  plants 
is  the  improvement  of  the  physical  condition  of  the  soil.  Deep 
rooted  plants  tend  to  make  a  soil  more  porous  because  the  de- 


34  FERTII.ITY   AND   FERTIUZER    HINTS 

cay  of  roots  leaves  passages  in  the  soil  which  aid  in  draining  and 
aerating  it.  Grass  crops  tend  to  make  a  soil  compact,  while  al- 
falfa, roots,  grains  and  other  cultivated  crops  tend  to  open  up 
the  soil. 

A  rotation  should  be  selected  to  keep  the  soil  in  good  physi- 
cal condition.  Sandy  soils  are  improved  by  crops  that  compact 
them  while  clay  soils  should  be  made  more  porous. 

ID.  Rotation  Saves  Fertilizer  Expenditure. — On  some  farms  that 
formerlv  used  150  to  300  pounds  of  commercial  fertilizer  per 
acre,  as  high  as  1,500  to  2,000  pounds  must  be  used  now  to  give 
the  same  yields.  A  proper  rotation  of  crops  will  save  the  em- 
ployment of  such  large  quantities  of  commercial  fertilizers.  Farm 
manure  may  be  used  and  commercial  fertilizer  only  applied  to 
those  crops  that  are  most  in  need  of  nourishment. 

11.  Rotation  of  Crops  Regulates  the  Humus  Supply. — Some 
crops  furnish  humus  while  others  tend  to  deplete  the  soil  of  this 
material.  Single  crop  farming  is  very  exhaustive  on  the  humus 
supply  of  the  soil  while  a  rotation  of  crops  should  be  selected 
to  conserve  the  humus  content  of  a  soil.  Grass  crops  tend  to 
increase  the  humus  supply,  while  grain,  cotton,  tobacco,  etc.,  have 
the  opposite  efifect  of  consuming  humus.  The  addition  of  farm 
manure  is  helpful  in  supplying  humus.* 

12.  A  Rotation  of  Crops  Conserves  Moisture. — In  the  arid 
regions  the  conservation  of  moisture  is  an  important  considera- 
tion in  planning  a  rotation.  Heavy  moisture  consuming  crops 
should  not  be  planted  in  succession  in  sections  of  small  rainfall, 
but  heavy  consuming  and  light  consuming  moisture  crops  should 
be  so  grown  as  to  conserve  the  moisture  supply.* 

System  of  Farming. — The  loss  of  fertility  sold  from  the  farm 
depends  upon  the  kinds  of  crops  produced  and  sold.  When 
live-stock,  butter  and  milk  are  sold  there  is  less  fertility  lost  than 
from  common  farm  crops.* 


CHAPTER  IV. 

FARM  MANURES. 

Karni  manure  has  been  used  for  centuries  in  restoring  fer- 
tility to  the  soil.  It  is  the  oldest  and  one  of  the  most  important 
of  our  fertilizers.  It  is  formed  from  vegetable  and  animal  sub- 
stances and  naturally  should  prove  of  great  value.  In  some  sec- 
tion of  this  country  farm  manure  is  w^asted,  but  the  value  of  this 
material  is  generally  becoming  better  understood  and  is  more 
carefully  saved  than  formerly,  especially  in  the  older  farming 
regions. 

Kinds  of  Manure. — When  there  is  a  great  deal  of  straw  or  hay 
in  manure,  it  is  said  to  be  coarse.  It  is  termed  stable  manure 
when  it  is  accumulated  in  stables  and  contains  all  the  solid  and 
liquid  portions.  Barnyard  manure  is  a  name  applied  to  manure 
which  is  subject  to  exposure  of  rains  and  sun  and  may  be  com- 
posed of  pure  solid  excrement,  or  excrement  and  bedding. 

Conditions  Affecting  the  Value  of  Manure. — There  are  many 
conditions  which  affect  the  value  of  manure. 

1.  The  age  of  the  animal. 

2.  The  use  of  the  animal. 

3.  The  kind  and  amount  of  bedding  used. 

4.  The  kind  of  animal. 

5.  The  nature  and  amount  of  feed  used. 

6.  The  care,  preservation  and  use  of  the  manure. 

1.  The  age  of  the  animal  influences  the  value  of  manure.  Ma- 
nure from  young  animals  is  not  so  rich  in  the  fertilizer  constitu- 
ents, nitrogen,  phosphoric  acid  and  potash  as  that  from  mature 
animals,  even  when  the  same  kind  of  feed  is  used.  Young  ani- 
mals require  and  retain  nitrogen  and  phosphoric  acid  for  growth, 
while  mature  animals  use  these  constituents  for  maintaining  the 
functions  of  the  body  and  for  repairing  broken  down  tissues, 
after  which  they  are  cast  off  in  the  manure. 

2.  The  use  of  the  animal  influences  the  value  of  manure.  Milch 
cows  return  less  of  the  fertilizing  constituents  in  the  feed  than 
other  domestic   farm   animals.     Fattening  pigs   return   less   than 


36  FERTILITY   AND  FERTILIZER    HINTS 

fattening  sheep  and  fattening  sheep  less  than  fattening  oxen. 
Horses  return  the  same  relative  amounts  from  the  feed  whether 
at  work  or  at  rest/'' 

3.  The  Kind  and  Amount  of  Bedding  Used. — Bedding  besides 
affecting  the  value  of  manure  renders  stables  more  sanitary.  It 
provides  comfort  for  the  animal,  makes  the  manure  lighter  and 
easier  to  handle,  absorbs  the  liquids,  lessens  fermentation  and 
improves  the  texture  of  the  manure. 

Straw  is  the  most  common  bedding  used  and  is  well  suited  for 
this  purpose,  because  it  is  largely  made  up  of  cellulose  which  is 
a  good  absorber  on  account  of  its  hollow  structure.*  There  is 
a  difference  in  the  composition  of  straws,  but  they  all  contain 
a  high  potash  content.  The  nitrogen  and  phosphoric  acid  are 
rather  low  and  when  large  amounts  of  straw  are  employed  the 
fertilizing  value  of  the  manure  is  naturally  lowered. 

Leaves. — Dried  autumn  leaves  are  often  gathered  and  used  as 
bedding.  They  are  not  as  valuable  as  straw  as  they  do  not  fer- 
ment very  rapidly  and  are  liable  to  cause  acidity  in  the  manure. 

Sawdust  is  often  used  as  bedding  and  it  is  much  inferior  to 
straw  and  dried  leaves  from  a  fertility  standpoint.  It  decom- 
poses very  slowly  in  the  soil.  However,  this  material  is  a  good 
absorber  of  the  liquid  portions  and  makes  a  good  bedding  when 
it  can  be  obtained  cheaply. 

Shavings  are  sometimes  used  as  bedding  and  possess  about  the 
same  properties  as  sawdust. 

Peat  when  dried  is  a  good  material  to  use  in  stables  as  it  is 
an  excellent  absorber.  It  absorbs  not  only  the  liquid  portions  of 
the  manure  but  also  the  nitrogen  gases  evolved,  and  renders  the 
stable  free  from  foul  odor.  It  in  itself  contains  considerable 
organic  matter  which  is  beneficial  and  it  is  readily  fermented  in 
the  soil.  It  is  a  good  material  to  use  in  conjunction  with  straw. 
The  use  of  peat  as  bedding  increases  the  nitrogen  content  of  the 
manure.  The  nitrogen  percentage  in  peat  varies  a  great  deal  but 
it  usually  approximates  i  to   1.5  per  cent. 

Absorptive  Power  of  Bedding. — According  to  Snyder,^  the  ab- 
sorptive power  of  different  kinds  of  bedding  are: 

*  Soils  and  Fertilizers. 


FARM     MANURES 


37 


Per  cent, 
of  water 
absorbed. 

Fine  cut  straw 30.0 

Coarse  uncut  straw iS.o 

Peat 60.0 

Sawdust 45.0 

Snyder  says :  "The  proportion  of  absorbents  in  manure  ranges 
from  a  fifth  to  a  third  of  the  total  weight  of  the  manure." 

The  following  experiment  shows  the  absorptive  power  of  straw 
and  peat  in  two  similar  stables  carrying  the  same  stock,  in  one 
of  which  straw  was  used  and  the  other  peat. 

Ammonia  in  Stable  Per  Million  of  Air.' 


c 

3d 

day 

4 

4th 
day 

day 

6th 
day 

J"" 
day 

.0012 

.0028 

.0045 

.0081 

•0153 
trace 

.0168 
.001 

Peat  moss 

.017 

4.  The  Kind  of  Manure. — Manure  from  different  kinds  of  ani- 
mals varies  in  value. 

Horse  Manure. — The  manure  voided  by  the  horse  is  rich  in 
nitrogen  and  not  so  finely  divided  as  the  nianure  from  cows, 
sheep,  etc.  This  is  due  to  the  horse  only  having  one  compart- 
ment in  its  stomach  and  therefore  the  feed,  especially  coarse  feed 
as  hay,  etc.,  is  less  broken  up  and  digested.  Horse  manure  is 
generally  comparatively  dry  and  hard  to  incorporate  with  bed- 
ding. On  this  account,  and  because  of  its  coarse  nature  and 
chemical  composition,  fermentation  readily  sets  in  and  consid- 
erable nitrogen  is  lost  unless  the  fermentation  is  stopped.  When 
fermentation  is  allowed  to  continue  the  value  of  horse  manure 
is  very  much  decreased.  Boussingault  found  by  experiment  that 
when  fermentation  was  allowed  to  continue,  one-half  of  the  nitro- 
gen was  lost  from  the  fresh  manure.* 

The  liquid  portion  of  horse  manure  contains  a  great  deal  more 
nitrogen  that  the  solid.  The  liquid  portion  of  horse  manure 
contains  very  little  phosphoric  acid. 

Cow  manure  is  much  colder  than  horse  manure  and  so  a  fine 
combination   results  when   it   is  mixed   with  horse  manure;  the 

'  Hall,  Fertilizers  and  Manures. 


38  FERTILITY    AND   FERTILIZER    HINTS 

fermentation  of  the  horse  manure  is  stopped  and  the  nitrogen 
saved,  and  the  mixture  is  better  than  cow  manure  alone.  Cow 
manure  contains  more  water  than  horse  manure  due  perhaps  to 
the  large  amount  of  water  drank  by  this  class  of  animal.  Cow 
manure  does  not  ferment  rapidly  and  when  dry  decomposes  very 
slowly  in  the  soil.  It  is  estimated  that  6  to  10  pounds  of  straw 
are  necessary  to  absorb  cow  manure,  depending  upon  the  amount 
of  liquids  voided. 

The  nitrogen  content  is  present  in  greatest  amount  in  the  liquids 
while  there  is  little  phosphoric  acid  present  in  this  portion  of 
cow   manure. 

Hog  Manure. — The  composition  of  hog  manure  is  quite  variable 
depending  upon  the  feed  consumed.  When  tankage  and  other 
highly  nitrogenous  feeds  are  employed  the  manure  is  rich,  but 
when  feeds  containing  small  amounts  of  fertilizing  constituents 
are  used,  the  manure  is  not  so  valuable.  Hog  manure  contains 
a  high  percentage  of  water  and  is  slow  to  decompose.  It  is  es- 
timated that  4  to  8  pounds  of  straw  are  adequate  for  absorbing 
pig  manure. 

The  liquid  portion  of  hog  manure  contains  more  phosphoric 
acid  and  the  solids  more  potash  than  horse  or  cow  manure. 
As  previously  mentioned,  the  nitrogen  content  of  the  liquid  por- 
tion of  hog  manure  depends  upon  the  nature  of  the  feed.  Some- 
times the  nitrogen  will  reach  1.5  per  cent,  in  the  liquid  portion. 
The  liquid  portion  is  higher  in  water  than  manure  from  other 
farm  live-stock. 

Sheep  Manure. — The  manure  from  sheep  is  more  valuable  than 
that  from  other  farm  animals.  On  account  of  its  being  dry  and 
rich  in  nitrogen  it  ferments  rapidly  although  not  so  quickly  as 
horse  manure.  The  slower  action  is  perhaps  due  to  its  more 
compact  mechanical  condition.  Losses  of  nitrogen  in  §heep  ma- 
nure are  apt  to  occur  unless  the  manure  is  well  taken  care  of. 
Both  the  solids  and  liquids  of  sheep  manure  run  higher  in  nitro- 
gen that  the  manure  from  other  farm  animals,  and  the  water  con- 
tent is  lower.  The  phosphoric  acid  content  of  the  solids  is  also 
high  and  that  of  the  liquids  appreciable.* 


ARM      MAM-RHS 


39 


Hen  manure  contains  its  nitrogen  in  a  quickly  available  form 
and  unless  carefully  preserved,  fermentation  sets  in  and  drives 
off  considerable  of  this  valuable  constituent  as  ammonia.  Lime 
should  not  be  used  where  the  manure  is  kept  as  it  hastens  the 
liberation  of  ammonia.  The  per  cent,  of  nitrogen  in  hen  manure 
depends  a  great  deal  on  the  kind  of  feed  consumed.  Hens  pro- 
duce, per  1,000  pounds  live  weight,  about  35  pounds  of  manure 
per  day,  and  about  one  bushel  of  manure  is  produced  by  a  hen 
per  year.  Hen  manure  approximates  sheep  manure  in  compo- 
sition.    It  is  a  valuable  manure  because  it  acts  quickly.* 

Analyses  of  Farm  Manures.' 


Kind  of  manure 

Vl^ater 
Per  cent. 

Nitrogen 
Per  cent. 

Pota.sh 
Per  cent. 

Phosphoric 

acid 
Per  cent. 

Cattle  (solid  fresh  excrement) 

Cattle  (fresh  urine)  •  •    

73-27 

0.29 
0.58 
1.63 
0.44 
1.55 
0.55 
1-95 
0.50 
0.60 
0.43 

0.10 
0.49 
0.85 
0.35 
1.50 
0.15 
2.26 
0.60 
0.13 
0.83 

O.I7 

1-54 
0.17 

Horse  (solid  fresh  excrement) 

Sheep  (solid  fresh  excrement) 

Sheep  ( fresh  urine )   

Stable  manure  (mixed  ) 

Swine  (solid  fresh  excrement ) 

0.31 
0.0  [ 
0.30 
0.41 
0.07 

How  to  Calculate  the  Amount  of  Manure  Produced. — A  method 
used  for  determining  the  amount  of  manure  produced  by  ani- 
mals is  to  multiply  the  amount  of  dry  matter  in  the  feed  con- 
sumed by  3.8  for  a  cow,  2.1  for  a  horse  and  1.8  for  a  sheep. 
A  horse  that  consumes  feed  containing  25  pounds  of  dry  matter 
per  day  would  void  25  X  2.1  =  52.5  pounds  of  manure  a  day. 
Add  to  this  the  amount  of  bedding  used  and  you  will  arrive  at 
the  total  amount  of  manure. 

5.  The  nature  and  amount  of  feed  used  afifects  the  value  of  the 
manure.  The  richer  the  feed  the  higher  the  fertilizing  value  of 
the  manure.  Coarse  feeds  like  hay,  straw,  etc.,  produce  less 
valuable  manure  than  concentraterl  feeds  like  linseed  meal,  gluten 
meal,  cotton-seed   meal,   etc.* 

'  Fletcher,  Soils. 

4 


40  FERTILITY   AND   FERTILIZER    HINTS 

Lasting  Effect  of  Manure. — The  lasting  effect  of  manure  is 
shown  by  the  experiments  conducted  at  Rothamstead.  A  plot  of 
grass  land  received  applications  of  14  tons  of  manure  per  acre 
for  8  consecutive  years  and  then  the  applications  were  discontin- 
ued. During  the  first  year  after  the  discontinuance  of  manure 
the  yield  was  twice  that  of  an  unmanured  plot.  Since  that  time 
the  yield  on  the  manured  plot  has  slowly  decreased  until  at  the 
end  of  40  years  the  excess  has  been  about  15  per  cent,  greater 
than  the  yield  of  the  unmanured  plot. 

An  experiment  was  conducted  with  barley.  Three  plots  were 
employed.  One  plot  received  14  tons  of  manure  per  acre  since 
1852,  another  received  14  tons  of  manure  per  acre  for  20  years 
and  then  the  applications  were  stopped,  and  the  third  has  been 
unmanured  since  1852. 

The  experiment  showed  that  the  continuously  manured  plot 
had  the  largest  yields  but  the  plot  that  was  measured  for  20 
years  is  still  producing  crops  at  least  40  per  cent,  greater  than 
the  unmanured  plot. 

The  results  in  these  experiments  would  not  be  found  to  be  so 
apparent  in  actual  farming,  as  the  soils  that  were  used  for  these 
experiments  were  more  exhausted  than  the  farmer  would  use. 
However,  the  results  are  interesting  as  they  show  the  almost 
permanent  effect  of  farm  manure  on  soils." 

6.  The  Care,  Preservation  and  Use  of  Manure. — From  the  fore- 
going pages  it  is  very  evident  that  the  composition  of  manure 
and  the  amounts  produced  by  different  kinds  of  animals  are  ex- 
ceedingly variable.  It  is  also  tnown  that  a  regular  value  for  this 
product  cannot  be  estimated  from  its  chemical  composition. 

Waste  of  Manure. — In  some  sections  of  the  United  States  farm 
manure  is  dumped  into  streams,  burned,  buried  in  holes  in  the 
ground,  or  allowed  to  remain  in  large  piles  in  some  uncultivated 
place.  The  soils  in  many  of  such  sections  are  fertile  enough  to 
produce  profitable  crops  but  it  seems  very  wasteful  to  throw 
away  such  valuable  fertilizer. 

Leaching. — When  a  manure  heap  is  exposed  to  the  washing  of 
rain  and  the  solutions  allowed  to  wash  away,  the  value  of  the 
manure  is  decreased.     The  soluble  plant  food  elements  are  washed 


FARM     MANURES 


41 


away  tog-ether  with  more  or  less  of  the  manure  itself.  Leaching 
is  one  of  the  most  important  subjects  to  consider  in  the  care  and 
preservation  of  manure  because  it  is  the  source  of  one  of  the 
greatest  losses  in  this  valuable  product.  Experiments  have  been 
conducted  to  show  the  great  losses  that  occur  by  leaching.  Horse 


,. 

^'^.-.,          mtGitiP^: 

^  ^^'^  -  U^^  -^    ■-  iilgll^^  ^  -a^ 

Pli^^fe 

.c^^^Bi^^i^*- /*^'i59 

'  '■  ■.■■..  -  \w,*j""^-''-;-'; -■   ■■*' 

----'.:       -r^^^^*-- 

Fig-.  1.  -The  mam 


from  live-stock  should  be  carefully  saved. 


manure  suffers  larger  losses  than  mixed  horse  and  cow  manure, 
or  cow  manure. "*' 

Fermentations. — There  are  certain  bacteria  that  produce  fer- 
mentations in  manure  piles  and  liberate  nitrogen  as  gas  causing 
large  losses  in  manure.  These  fermentations  are  brought  about 
by  two  classes  of  organisms  ;  aerobic  bacteria  and  anaerobic  bac- 
teria. 

I.  The  aerobic  bacteria  require  oxygen  to  be  active  and  the 
anaerobic  bacteria  are  only  active  in  the  absence  of  oxygen.  On 
the  outside  of  manure  heaps  where  air  circulates,  the  aerobic 
bacteria  work  while  in  the  interior  of  the  heaps  where  no  air 


42  FERTILITY   AND  FERTILIZER   HINTS 

can  penetrate  the  anaerobic  fermentation  takes  place.  The  aerobic 
bacteria  convert  the  nitrogen  present  in  the  organic  matter  of 
the  manure,  into  ammonia,  in  which  form  it  passes  off  into  the 
atmosphere.  Because  of  the  great  amount  of  carbon  dioxide 
formed  during  this  action  some  of  the  ammonia  is  converted  into 
carbonate  of  ammonia  which  is  also  volatile. 

2.  The  anaerobic  bacteria  convert  ammonia  salts  to  nitrogen, 
v^ome  of  these  bacteria  have  the  power  of  reducing  nitrates  to 
nitrites,  and  to  ammonia.  The  anaerobic  bacteria  do  not  bring 
about  such  losses  as  the  aerobic  bacteria,  so  it  is  important  to 
keep  the  manure  heap  well  compacted  to  prevent  the  action  of 
the  aerobic  organisms. 

Keep  the  Manure  Moist. — Dry  manure  ferments  more  readily 
than  wet  manure.  To  prevent  active  fermentation  the  manure 
heap  should  be  kept  moist.  It  is  not  necessary  to  add  enough 
water  to  leach  it.  Water  excludes  the  air  and  promote  anaerobic 
action  which  is  beneficial.* 

The  temperature  in  fermenting  horse,  sheep  and  poultry  ma- 
nure often  goes  higher  than  150°  Fahrenheit  (65°  Centigrade). 
The  highest  temperature  is  usually  near  the  surface  as  the  fer- 
mentation is  most  active  there. 

Composting  manure  is  helpful  in  increasing  the  availability  of 
that  plant  food.  It  also  kills  many  weed  seeds.  There  is  less 
loss  of  plant  food  when  the  manure  is  applied  to  the  soil  fresh, 
than  when  allowed  to  rot.  It  is  not  generally  convenient  to  haul 
the  manure  from  the  stable  to  the  land  as  other  work  is  of 
more  importance,  so  that  the  manure  has  to  be  stored  until 
the  regular  farm  work  becomes  slack.  When  manure  is  com- 
posted  it  should  be  kept  compact  and  moist  and  the  heap  should 
be  shaped  to  shed  water.  A  layer  of  earth  on  the  top  of  the 
manure  compost  will  tend  to  absorb  some  of  the  gases. 

Voelcker^  gives  the  following  as  the  composition  of  fresh  and 
rotted  manure. 

'  I.yon  and  Fippin,  Soils. 


P'ARM     MANURES 


43 


Rotted 
Per  cent. 


Water 

Soluble  organic  matter.  . . . 
Soluble  organic  nitrogen.  . 
Soluble  inorganic  matter-  . 
Insoluble  organic  matter- . 
Insoluble  inorganic  matter 


75-42 
3-71 
0.30 
1.47 

12.82 
6-58 


It  is  seen  that  manure  that  is  composted  contains  the  fertilizer 
elements  in  a  more  available  form  than  in  fresh  manure. 

The  organic  matter  is  decreased  by  allowing  manure  to  rot. 
Snyder^  says :  "A  ton  of  composted  manure  is  obtained  from 
2,800  pounds  of  stable  manure."  There  are  of  course  some 
losses  of  nitrogen  in  composting  manure,  the  extent  of  these 
losses  depending  upon  the  compactness  and  dryness  of  the  ma- 
nure. 

The  principal  benefits  derived  from  composting  manure  are ; 
the  improvement  of  the  physical  condition,  and  decomposition 
takes  place  in  the  manure  that  ordinarily  would  have  to  be 
performed    in   the    soil. 

Sometimes  manure  is  composted  with  earth,  sod,  leaves  and 
wastes  from  the  farm. 

Store  Manure  Under  Cover. — Whenever  manure  is  left  out  of 
doors  exposed  to  the  rain  losses  occur.  Many  farmers  preserve 
manure  in  different  ways.  Some  use  covered  yards  where  the 
stock  are  allowed  to  exercise  and  the  manure  is  kept  compact 
by  the  tramping  of  the  animals.  In  this  practice  bedding  should 
be  used  to  absorb  all  of  the  liquids  and  to  allow  the  animals 
to  be  comfortable.  The  site  should  be  well  drained  and  kept 
dry.  The  manure  from  sheep,  hogs,  young  stock,  etc.,  is  often 
preserved  in  this  way.  Some  farmers  keep  the  manure  in  cel- 
lars under  the  stable.  The  fermentation  of  manure  in  the  cellar 
of  a  stable  is  liable  to  produce  foul  odors  and  is  especially  ob- 
jectionable in  dairy  barns.  Another  method  of  storing  ma- 
nure that  is  used  in  the  older  farming  sections,  especially  in 
dairies,  is  to  build  covered  cement  pits  just  outside  the  bam  and 
dump  the  manure  from  trucks.     The  liquid  portions  arc  drained 

'  Soils  and  Fertilizers. 


44 


FERTILITY   AND  FERTILIZER    HINTS 


to  these  pits  by  pipes.  It  may  not  always  be  possible  for  a  farm- 
er to  build  a  covered  cement  pit  but  he  can  always  afford  to 
put  a  roof  over  the  manure,  for  the  cost  of  the  shed  will  soon  be 
returned  in  the  increased  value  of  the  manure. 

The  following  table,  the  work  of  Biernatski,  shows  the  com- 
position of  uncovered  and  covered  manure. 


Water 
Per  cent. 

Nitrogen 
Per  cent. 

Phos^^horic 
Per  cent. 

Potash 
Per  cent. 

Uncovered  manure 

Covered  manure 

83.78 
76.54 

0.47 
0.67 

0.26 
0.31 

Ife 

Preservatives. — In  the  destruction  of  the  nitrogen  present  in 
organic  matter  in  manure,  the  aerobic  bacteria  produce  ammonia 
and  some  of  this  gas  unites  with  the  carbon  dioxide  evolved  and 
forms  ammonium  carbonate,  a  volatile  compound.  By  adding 
moist  gypsum  (land  plaster)  to  manure,  the  ammonium  carbo- 
nate is  converted  into  ammonium  sulphate,  a  compound  that  ,does 
not  pass  away  in  the  atmosphere.  This  latter  compound  is  solu- 
ble in  water  and  when  manure  is  exposed  to  the  leaching  of  rains, 
it  is  useless  to  employ  gypsum.  Gypsum  is  perfectly  safe  to  use 
because  it  does  not  injure  the  feet  of  animals.  Lime  is  objec- 
tionable because  it  liberates  ammonia.  Kainit,  superphosphate 
and  ground  rock  phosphate  are  sometimes  used  with  good  suc- 
cess, as  they  absorb  nitrogen.  These  preservatives  may  be  scat- 
tered at  the  rate  of  about  one  pound  to  an  animal.  They  may  also 
be  economically  used  on  covered  manure  heaps.  HalP  estimates 
that  it  will  take  about  100  pounds  of  gypsum  per  ton  of  manure 
to  absorb  the  leases,  as  some  of  it  is  acted  upon  by  the  potassium 
carbonate  in  the  urine. 

Physical  Effects  of  Manure.— Manure  has  a  greater  value  than 
is  represented  by  its  chemical  composition.  It  improves  the  phy- 
sical condition  of  the  soil  by. 

1.  Producing  a  better  moisture  condition. 

2.  Producing  a  better  texture. 

3.  Preventing  mechanical  losses  by  winds. 

4.  Benefiting  grass  land. 
'  Fertilizers  and  Manures. 


FARM     MANURKS  45 

1.  Manure  Produces  a  Better  Moisture  Condition. — Manure  when 
added  to  soils  increases  the  water  holding  power  of  those  soils 
because  of  its  humus  content.  Humus  absorbs  water  readily. 
A  soil  that  has  had  manure  added  to  it  will  resist  drought  better 
than  one  where  there  is  little  or  no  humus.  During  a  heavy 
rainfall  the  soil  with  humus  will  absorb  a  great  deal  more  water 
and  give  it  up  more  gradually  than  one  without  humus.*  Manure 
helps  to  conserve  the  moisture  supply  of  soil  during  dry  seasons. 

2.  Manure  Improves  the  Texture  of  the  Soil. — Manure  has  a 
very  beneficial  effect  on  most  soils  in  improving  the  texture. 
The  addition  of  manure  to  sandy  soils  makes  them  more  binding 
and  increases  their  water  holding  capacity.  Clay  soils  are  made 
niore  porous  by  the  addition  of  manure.  Some  soils  may  pro- 
duce good  crops  during  favorable  seasons  without  much  organic 
matter  but  when  the  season  is  bad  it  is  almost  impossible  to  get 
the   soil   in   good   mechanical   condition    for   crops. 

Number  of  Mangoi^d  Plants  Taking  ioo  as  the  Possible.' 
Average  of  7  years,  1901-7. 


Farm  manure,  minerals 
and  nitrate  of  soda 

Minerals  and 
nitrate  of  soda 

Minerals  and 
rape  cake 

69 

62 

S3 

The  plot  receiving  rape  cake,  which  was  applied  at  the  rate 
of  2,000  pounds  per  year,  shows  the  best  results,  but  rape  cake 
like  manure  supplies  a  great  deal  of  humus.  A  better  stand  was 
produced  with  farm  manure  than  with  the  artificial  fertilizer. 

3.  Manure  Prevents  Mechanical  Losses  by  Winds. — The  losses 
occasioned  by  heavy  winds  on  certain  soils  are  sometimes  more 
than  one  would  expect.  Dry  light  soils  devoid  of  organic  mat- 
ter are  easily  blown  away  by  heavy  winds.  The  addition  of  ma- 
nure to  such  soils  tends  to  keep  them  moist  and  prevents  such 
loss. 

4.  Manure  Benefits  Grass  Land. — Manure  benefits  grass  land 
not  only  by  supplying  plant  food  and  increasing  the  moisture  hold- 
ing capacity,   but   also   in   protecting  this   crop   from   the   frosts 

1  Hall,  Fertilizers  and  Manures. 


46 


FERTILITY   AND  FERTILIZER    HINTS 


of  early  spring,  by  the  mulch  produced.  It  is  noticed  that  grass 
that  has  been  manured  in  the  fall  has  an  earlier  growth  in  the 
spring  than  such  lands  unmanured. 

Bacteriological  Effects  of  Manure. — Manure  when  added  to  the 
soil  aids  the  growth  of  bacteria  that  render  plant  food  available. 
It  also  increases  the  number  of  these  bacteria  and  supplies  food 
for  them,  and  fermentations  are  promoted  that  are  very  helpful 
in  the  production  of  crops. 

Time  to  Apply  Manure. — In  order  to  get  all  the  value  from  farm 
manure  it  is  better  to  apply  it  while  fresh  than  when  rotted. 
Manure  in  rotting  loses  some  of  its  fertility.  The  Ohio  Experi- 
ment Station  have  conducted  experiments  with  fresh  manure  and 
exposed  yard  manure  with  the  following  crop  returns  for  ten 
years. 


Amount 

applied 

per  acre 

tons. 

Yield  per  acre. 

Corn 
bushels. 

Wheat             Hay 
bushels.        pounds. 

s 

8 

16.03 
22.24 

821                  6q8 
9  73           1.280 

The  manure  was  applied  to  clover  sod  which  was  plowed  under 
and  followed  by  a  three  year  rotation  of  corn,  wheat  and  clover 
without  the  addition  of  any  more  manure.  The  yields  favor  the 
fresh  manure  with  an  increase  of  6.21  bushels  of  corn,  1.52 
bushels  of  wheat  and  582  pounds  of  hay. 

Sometimes  it  is  not  practicable  to  apply  manure  while  fresh 
as  some  crops,  especially  the  quick  growing  market  garden  crops, 
require  plant  food  that  is  available  and  so  prefer  rotted  manure. 

It  is  common  in  this  country  to  apply  fresh  manure  to  grass 
land  in  the  fall  and  turn  it  under  in  the  spring.  This  practice 
is  beneficial  in  that  it  supplies  a  great  deal  of  organic  matter  for 
the  .succeeding  crop.  Corn  is  a  crop  that  thrives  on  fresh  manure 
and  so  it  is  well  to  apply  manure  in  this  condition  to  corn  and 
follow  this  crop  with  one  that  prefers  rotted  manure. 

Amount  of  Manure  to  Apply. — The  amount  of  manure  to  ap- 
ply  depends   upon   the   fertility   and   texture   of   the   soil.     Soils 


FARM     MANURES  47 

that  already  have  considerable  fertility  sometimes  require  a  light 
application  of  manure  to  improve  their  texture.  Large  applica- 
tions of  manure  on  such  soils  would  not  be  profitable.  Most 
farmers  use  too  much  on  their  land  at  one  time.  Frequent  light 
applications  are  more  beneficial  than  large  amounts  applied  at 
long  intervals,  as  they  keep  the  soil  in  an  even  state  of  fertihty 
and  losses  by  volatilization  of  nitrogen  as  gases  and  leaching  of 
the  soluble  elements  are  less.  Experiments  show  that  small  ap- 
plications give  greater  percentage  increase  than  large  applications 
although  large  applications  give  larger  yields. 

Sometimes  manure  does  not  furnish  sufficient  plant  food  to 
satisfy  t^ie  needs  of  the  crop.  An  addition  of  some  commercial 
fertilizer  which  supplies  the  necessary  fertihzer  constituents  is 
beneficial  in  such  cases  to  supplement  the  manure. 

How  to  Apply  Manure. — It  is  best  to  spread  the  manure  over 
the  land  as  it  is  hauled.  Some  farmers  dump  the  manure  in  little 
piles  over  the  field  and  leave  it  in  this  condition  for  two  or  three 
months.  When  fermentations  take  place  in  these  piles  nitrogen 
passes  off  in  the  air.  This  practice  is  objectionable  because  the 
soil  under  and  around  the  piles  gets  most  of  the  available  plant 
food  that  is  leached  out,  and  the  other  soil  does  not  receive  its 
share.  The  result  is  that  the  succeeding  crops  grow  uneven  or  in 
patches.  There  is  no  objection  to  dumping  manure  in  small 
piles  over  the  field  if  it  is  spread  immediately.  The  hauling  of 
manure  to  the  field  and  hand  spreading  it  is  perhaps  the  common 
method  used  in  this  country.  It  is  difficult  to  spread  manure 
evenly  in  this  way  and  after  the  manure  is  distributed,  a  brush 
drag  should  be  used  to  scatter  it  more  evenly.  Manure  spreaders 
distribute  manure  more  evenly  than  any  of  the  other  methods  in 
use.  They  are  labor  saving  machines  and  although  they  usually 
carry  less  per  unit  of  draft,  they  are  considered  a  good  invest- 
ment for  those  who  have  much  manure  to  spread.  A  ton  of 
manure  spread  uniformly  gives  better  results  than  a  larger  amount 
applied  unevenly. 


CHAPTER  V. 


HIGH  GRADE  NITROGENOUS  FERTILIZER  MATERIALS. 

Nitrogen  is  the  most  important  element  to  consider  in  the  study 
of  fertihzers.  It  is  the  most  expensive  and  most  fugitive  of  the 
essential  elements.  Nitrogen  usually  costs  about  three  times  as 
much  as  phosphoric  acid  or  potash.  To  be  in  a  form  available 
as  plant  food  it  must  be  as  nitrates  which  are  readily  soluble  in 
water.  The  air  is  made  up  of  nitrogen,  carbon  and  oxygen  and 
although  plants  utilize  the  carbon  and  oxygen  most  of  them  do 
not  seem  to  be  able  to  use  the  nitrogen.  There  is  one  class  of 
plants,  the  legumes  (peas,  beans,  peanuts,  alfalfa,  clover,  etc.) 
of  which  we  have  spoken,  that  can  utilize  this  elementary  nitro- 
gen but  most  of  our  other  plants  do  not  possess  this  power. 
The  organic  matter,  which  is  made  up  of  animal  and  vegetable 
matter,  serves  as  a  source  of  nitrogen,  but  plants  cannot  use  it 
in  this  form.  It  is  understood  then  that  there  is  plenty  of  un- 
usuable  nitrogen  in  the  air  and  in  soils  rich  in  organic  matter,  but 
it  has  no  direct  plant  food  value  in  these  forms  until  it  is  prepared 
by  electrical  means,  oxidized  and  acted  upon  by  certain  bacteria. 

Forms  of  Nitrogen. — Nitrogen  exists  in  different  forms  in  the 
many  substances  containing  it.  Not  including  the  nitrogen  in  the 
air  we  may  classify  these  forms  into  four  groups,  namely : 

1.  Organic  nitrogen,  which  is  found  in  vegetable  and  animal 

substances,  generally  as  protein. 

2.  Ammonia  nitrogen,  which  is  found  in  ammonium  sulphate. 

3.  Nitrate  nitrogen,  which  is  found  in  nitrate  of  soda   (Chile 

saltpeter)  and  nitrate  of  potash. 

4.  Cyanamid  nitrogen,  which  is  taken  from  the  air  by  electrical 

means  and  combined  with  calcium,   carbon,  etc. 

Of  these  four  forms  all  are  soluble  in  water  except  organic 
nitrogen.  The  organic  form  is  included  in  many  substances, 
both  animal  and  vegetable,  while  the  remaining  forms  are  found 
principally  in  a  few  products. 

The  Meaning  of  the  Form  of  Nitrogen. — The  fertilizer  mater- 
ials furnishing  nitrogen  contain  this  element  in  different  forms. 


HIGH    GRADK    NITROGENOUS    FERTILIZKR    MATERIALS  49 

We  have  said  that  the  substances  containing  nitrate  nitrogen,  am- 
monia nitrogen  and  cyanamid  nitrogen  are  'sokible  in  water  and 
the  organic  nitrogen  is  insokible  in  water.  The  nitrogen  as  ni- 
trates is  ahvays  the  same  and  of  equal  vahie  no  matter  from  what 
substance  it  is  derived.  The  ammonia  nitrogen  is  also  of  equal 
value  and  equal  quantities  of  it  are  as  good  no  matter  what 
material  it  comes  from.  The  soluble  nitrogen  from  ammonium 
sulphate,  however,  is  not  the  same  as  the  soluble  nitrogen  from 
nitrate  of  soda  and  the  insoluble  nitrogen  of  organic  materials 
is  not  the  same  or  of  equal  value.  Therefore  the  source  of 
soluble  and  insoluble  nitrogen  makes  a  difference  in  value  of  the 
forms  oi  nitrogen.  The  solubility  of  nitrogenous  substances  in- 
fluences the  availability,  or  the  rate  with  which  the  nitrogen  in 
a  suitable  form  is  supplied  so  that  the  plant  can  assimilate  it, 
to  some  extent. 

The  organic  form  of  nitrogen  is  so  called  because  the  nitrogen 
is  combined  with  other  elements  as  hydrogen,  carbon  and  oxygen 
in  organic  matter.  Organic  nitrogen  is  different  in  the  various 
substances.  Some  animal  and  vegetable  materials  are  quite  rich 
in  nitrogen  while  others  do  not  contain  much  and  are  perhaps 
not  so  valuable.  Some  organic  substances  may  contain  consid- 
erable amounts  of  nitrogen  but  in  such  a  locked-up  state  that  they 
are  undesirable  as  plant  food. 

When  a  substance  gives  up  its  nitrogen  as  nitrates  readily  we 
say  that  the  nitrogen  is  in  a  form  that  is  active;  it  is  quick  acting, 
quickly  available,  readily  assimilated,  etc.  When  the  nitrogen  is 
locked-up  we  use  the  terms  slow  acting,  slowly  available,  etc. 
There  are  many  degrees  of  availability  of  the  different  forms  of 
nitrogen  and  they  range  from  the  very  quick  acting  of  the  soluble 
materials  to  the  organic  materials  that  may  take  two  or  three 
years  or  even  longer  before  they  give  up  their  nitrogen  for 
plants  to  use  as  food.  There  are  many  organic  substances  that 
contain  nitrogen,  but  in  such  small  amounts,  or  in  such  a  locked- 
up  condition  that  they  cannot  be  used  profitably  in  the  manufac- 
ture of  fertilizers. 

The  principal  sources  of  organic  nitrogen  will  now  be  discussed. 


50         ,  FERTILITY   AND   FERTILIZER    HINTS 

The  Vegetable  Substances. 

Cotton-seed  meal  is  one  of  the  most  important  sources  of 
vegetable  nitrogen.  It  is  usually  a  bright  yellow  product  with 
a  nutty  odor  when  fresh.* 

For  the  year  1908,  929,287,467  pounds  of  cotton-seed  meal 
were  manufactured  in  the  United  States.^ 

Yields  of  Products  from  a  Ton  of  Cotton-Seed."^ 

Pounds 

Linters 23 

Hulls 943 

Crude  oil  ( 37.6  gals. ) 282 

Cake  or  meal 713 

Waste  39 

Total 2,000 

Composition  of  Cotton-seed  Meal. — The  composition  of  cotton- 
seed meal  varies  a  great  deal.  When  it  is  not  adulterated  with 
hulls  the  variation  in  composition  may  be  due  to  the  season,  the 
nature  of  the  soil  and  the  climate.  Seed  raised  on  high  land  is 
usually  richer  in  nitrogen  than  seed  raised  on  low  land.  The 
Texas  meals  seem  to  run  high  in  nitrogen.  In  the  past  few 
years  many  of  the  manufacturers  have  been  introducing  ground 
cotton-seed  hulls  into  their  meal  which  of  course  lowers  the  value 
of  this  product.  Cotton-seed  meal  is  in  great  demand  as  feed 
for  live-stock  and  the  bright  yellow  meals  are  used  for  this  pur- 
pose. The  darker  meals  are  not  so  valuable  as  feed  and  are 
usually  sold  for  fertilizer.  The  dark  color  may  be  due  to  over- 
cooking, to  fermentation,  or  to  storing  in  a  wet  or  damp  place. 
If  there  is  no  loss  of  nitrogen,  the  product  is  not  injured  for 
fertilizing  purposes.* 

Value  of  Cotton-seed  Meal. — Large  quantities  of  this  product 
are  used  in  the  South  where  it  is  especially  suitable  for  the  long 
growing  crops  as  it  supplies  plant  food  during  the  whole  season. 

An  insect,  called  the  boll  weevil,  is  reducing  the  acreage  and 
yield  of  this  crop.     If  the  entomologists  do  not  find  a  way  of 

1  1908  Yearbook,  U.  S.  Dept.  of  Agriculture. 

2  Lamborn,  Cotton-Seed  Products. 


HIGH    GRADK    NITROGENOUS    FERTILIZER    MATERIALS  5 1 

checking  this  pest  the  use  of  cotton-seed  meal  will  be  much  less 
in  the  future. 

A  physical  examination  will  not  always  indicate  its  fertilizing 
value.  Many  of  the  meals  have  the  hulls  so  finely  ground  that  it 
is  impossible  to  detect  the  extent  of  their  presence  with  the  naked 


Fig.  5. — A  field  of  cotton,  the  source  of  cotton-seed  meal. 

eye.  The  color  of  a  meal  is  not  always  an  indication  of  it.s 
nitrogen  content.  Always  purchase  cotton-seed  meal  under  a 
strict  guarantee  as  this  product  is  variable  in  composition  and  a 
physical  examination  of  it  does  not  show  its  fertilizing  value. 
Linseed  meal  is  another  vegetable  compound  used  for  fertiliz- 
ing purposes.  It  is  a  by-product  in  the  manufacture  of  oil  from 
flaxseed.  There  are  two  classes  of  linseed  meal,  namely,  the  old 
and  new  process  meal.  The  old  process  meal  is  obtained  by  press- 
ing out  the  oil  from  the  cold  or  warmed  crushed  flaxseeds.  In 
the  new  process  the  oil  is  extracted  with  naphtha  and  the  naphtha 
driven   off  by   steam.     The   old   process   and   new   process   meal 


52  FERTILITY    AND   FERTILIZER    HINTS 

average  about  5.3  per  cent,  nitrogen,  1.25  per  cent,  potash  and 
1.6  per  cent,  phosphoric  acid.  Linseed  meal  is  not  used  ex- 
tensively as  fertilizer  because  of  the  high  price  it  commands  as 
feed  for  live-stock. 

Castor  pomace  is  the  remaining  product  from  the  extraction 
of  oil  from  the  castor  bean.  It  is  poisonous  to  live-stock  and 
therefore  is  used  for  fertilizer.  It  averages  about  5.5  per  cent, 
nitrogen,  1.8  per  cent,  phosphoric  acid  and  i  per  cent,  potash. 
As  it  decomposes  rapidly  in  the  soil  it  makes  an  excellent  fer- 
tilizer.* 

The  Chief  Animal  Substances. 

Dried  blood  is  obtained  from  the  large  packing  houses  of  the 
United  States.  There  are  two  kinds  on  the  market,  namely,  red 
and  black  blood.  The  red  blood  is  obtained  by  drying  blood  very 
carefully  with  superheated  steam  and  hot  air.  Should  the  blood 
be  dried  at  too  high  a  temperature  it  chars  and  turns  black.  If 
the  blood  is  injured  in  any  way  it  is  sold  as  black  blood.  Red 
blood  averages  about  13.5  per  cent,  nitrogen  with  traces  of  phos- 
phoric acid  while  black  blood  is  a  more  variable  product  but 
usually  contains  12  per  cent,  nitrogen  and  i  to  3  per  cent,  phos- 
phoric acid,  depending  upon  the  nature  of  the  impurities.  When 
bone  is  present  the  product  contains  sometimes  as  high  as  4  per 
cent,  phosphoric  acid.  Red  blood  is  not  used  for  fertilizer  be- 
cause it  commands  too  high  a  price  for  other  purposes.  Both  red 
and  black  blood  are  ground  and  sold  in  a  powdery  condition. 
Black  blood  is  a  very  valuable  nitrogenous  fertilizer  which  is 
in  great  demand  and  is  very  popular  with  the  manufacturers  of 
fertihzers  in  satisfying  their  formulas.  It  is  one  of  the  principal 
organic  fertilizers  used  by  manufacturers  in  the  North.  It  is 
not  used  directly  to  any  extent  by  farmers  as  the  manufacturers 
purchase  most  of  it.  It  is  in  a  fine  mechanical  condition  and  is 
easy  to  mix  with  other  materials.  As  plant  food  it  gives  ex- 
cellent results  as  it  decays  very  rapidly  thus  furnishing  nourish- 
ment during  the  early  stages  of  the  growing  period.  Sometimes 
salt  and  slaked  lime  are  put  in  blood.  It  is  very  high  in  avail- 
ability  being   somewhat   quicker  than   cotton-seed  meal. 


HIGH   GRADE  NITROGKNOUS  FKRTILIZKK    MATKRIALS  53 

Tankage  is  composed  entirely  of  animal  matter.  It  is  the  re- 
fuse from  slaughter  houses  and  consists  of  meat,  bone,  etc.  (from 
which  the  fat  has  been  extracted)  and  more  or  less  dried  blood. 
Animals  condemned  as  unsuitable  for  food  are  made  into  tankage. 

The  phosphoric  acid  in  tankage  is  slowly  available  as  it  is  sup- 
plied principally  by  ground  bone.  The  nitrogen  is  derived  prin- 
cipally from  meat  and  blood.  When  the  percentage  of  bone 
is  large,  the  phosphoric  acid  is  high,  and  the  nitrogen  content  is 
low,  and  when  there  is  an  excess  of  blood  and  meat,  the  ni- 
trogen is  high  and  the  phosphoric  acid  low. 

Grades  of  Tankage. — There  are  several  grades  of  tankage  found 
on  our  markets.  The  most  popular  nitrogenous  grades  are  those 
containing  8,  9,  and  10  per  cent,  ammonia  which  are  equivalent 
to  6.58,  7.41,  and  8.23  per  cent,  nitrogen,  and  6.56,  7.64,  10,  and 
12  per  cent,  bone  phosphate  of  lime,  which  are  equivalent  to 
3>  3-5)  4-58.  and  5.5  per  cent,  phosphoric  acid.  There  are  many 
other  grades  of  tankage  sold  that  carry  more  phosphoric  acid  and 
less  nitrogen,  but  these  are  classed  as  bone  tankages  and  will 
be  later  described  under  phosphates. 

Concentrated  tankage  is  still  another  grade  and  the  richest 
of  all  since  it  contains  more  nitrogen  and  is  a  more  uniform 
product.  It  is  made  by  evaporating,  wastes  that  contain  animal 
matter  in  solution,  or  in  other  words  the  tank  water.  It  us- 
ually contains  10  to  12  per  cent,  nitrogen  and  small  amounts 
of  phosphoric  acid. 

Variation  in  Tankage. — Because  of  the  great  variation  in  the 
chemical  composition  of  tankage  (no  two  shipments  hardly  ever 
run  alike,  for  the  manufacturers  cannot  seem  to  control  the  com- 
position of  their  output  on  account  of  the  variation  in  the  by- 
products), great  care  must  be  exercised  in  purchasing.  The  prod- 
uct should  be  bought  on  its  chemical  composition  and  not  nec- 
essarily on  its  guarantee,  for  it  may  or  may  not  reach  its  stated 
composition.  Hoof  meal  and  hair  are  sometimes  present  in 
shipments  of  tankage.  For  sugar-cane,  cotton-seed  meal  has 
been  found  to  be  more  valuable  than  tankage  of  the  same  ni- 
trogen   content.     Nevertheless,    tankage    is    a    valuable    fertilizer 


54  FERTILITY   AND    FERTILIZI^R    HINTS 

and  its  value  depends  a  great  deal  on  its  nitrogen  content.     It  is 
suitable  for  crops  having  a  long  growing  season. 

About  1,000,000  tons  of  tankage  and  dried  blood  are  produced 
annually. 

Azotin,  meat  meal,  flesh  meal,  dried  meat,  animal  matter  and 
ammonite  are  practically  the  same  product,  but  are  by-products 
from  different  manufacturing  establishments.  Most  of  this  prod- 
uct comes  from  the  slaughtering  houses  and  beef  extract  factor- 
ies. It  is  a  rich  organic  fertilizer  containing  about  13  per  cent, 
nitrogen,  but  it  may  run  higher  or  lower  than  this  depending 
upon  its  purity.  This  product  is  made  up  generally  of  the  flesh 
refuse  of  dead  animals  from  which  the  fat  has  been  extracted 
and  the  remains  dried  and  ground.  It  is  different  from  tankage 
because  it  does  not  contain  bones. 

Steamed  horn  and  hoof  meal  averages  about  12  to  15  per  cent, 
nitrogen  and  is  principally  marketed  by  the  large  packing  houses. 
The  choice  horns  and  hoofs  are  sold  for  the  manufacture  of 
buttons,  combs,  and  novelties,  and  the  imperfect  and  off-col- 
ored horns  and  hoofs  are  treated  with  steam,  under  high  pres- 
sure, which  renders  the  nitrogen  more  available  and  permits  of 
the  product  being  ground  to  a  fine  powder.  Horn  and  hoof 
meal  was  not  formerly  thought  much  of,  but  since  it  has  been 
subjected  to  superheated  steam  the  product  has  been  much 
sought  after  by  the  manufacturers  of  fertilizers.  It  is  produced 
only  in  limited  quantities  and  is  not  as  valuable  as  dried  blood, 
but  has  a  fairly  high  degree  of  availability,  according  to  recent 
investigations.* 

Dry  Ground  Fish. — This  is  also  called  fish  scrap  and  fish  guano 
and  has  a  yellow  color.  It  is  obtained  principally  from  canning 
factories  where  the  refuse  as  bones,  skin,  heads,  fins,  tails,  in- 
testines, etc.,  of  edible  fish  are  saved,  dried  and  ground.  Estab- 
lishments expressing  oil  and  manufacturing  glue  from  inedible 
fish  as  Menhaden,  furnish  a  considerable  supply.  The  average 
annual  catch  of  Menhaden  is  about  600,000,000  fish,  which  pro- 
duce 70,000  tons  of  fish  scrap  and  35,000  barrels  of  oil.  Thirty 
factories  with  70  steamers  are  engaged  in  this  industry  and  the 


HIGH    GRADE    NITROGENOUS   FERTILIZER    MATERIALS  55 

largest  catch  was  in  1903  when  1,000,000,000  fish  were  caught.' 
The  whale  bone  interests,  after  the  bones  are  removed  and  the 
oil  extracted  from  whales,  utilize  the  remainder  in  the  prepara- 
tion of  dry  ground  fisR. 

Dried  ground  fish  is  variable  in  composition  depending  upon 
the  nature  of  the  materials  of  which  it  is  made.  The  greater  the 
percentage  of  bone,  the  higher  is  the  phosphoric  acid  content  and 
the  lower  the  nitrogen,  and  the  less  bone,  the  higher  the  nitrogen 
and  the  lower  the  phosphoric  acid.  The  amount  of  oil  left  also 
influences  the  composition.  It  usually  ranges  from  7.5  to  10.5 
per  cent,  nitrogen,  5.7  to  16  per  cent,  phosphoric  acid,  with  an 
average'of  8.5  per  cent,  nitrogen  and  9  per  cent,  phosphoric  acid. 
It  is  a  popular  and  valuable  fertilizer  and  large  quantities  are 
used  in  the  North.  Most  sections  of  the  South  are  too  far  away 
from  where  it  is  manufactured  to  prevent  using  it  at  its  market 
value.  Dry  ground  fish  is  readily  decomposed  in  the  soil  and  is 
therefore  quick  acting.  It  is  not  considered  as  valuable  as  dried 
blood. 

King  crab  is  obtained  on  the  Atlantic  coast  and  is  dried  and 
ground,  in  which  state  it  is  utilized  by  fertilizer  manufacturers. 
It  contains  about  10  per  cent,  nitrogen  and  is  similar  to  dried 
ground  fish  in  fertilizer  properties. 

Guano,  or  natural  guano,  is  another  important  source  of  ni- 
trogen. It  w^as  used  as  early  as  the  12th  century  in  Peru.  On 
the  west  coast  of  South  America  there  are  thousands  of  sea  fowl. 
These  birds  have  roosting  and  breeding  places  along  the  unin- 
habited portions  of  the  coast  and  many  of  them  make  their  home 
on  the  smaller  islands  oflf  the  coast  of  Peru  and  also  on  the  main- 
land, because  of  the  abundant  supply  of  fish  in  that  region.  The 
excrement  voided  by  these  birds  is  rich  in  nitrogen  and  phosphoric 
acid  because  their  food,  which  is  fish,  is  rich  in  these  constit- 
uents. During  breeding  seasons  they  literally  cover  these  is- 
lands and  the  young  birds  after  they  are  hatched  are  fed  on 
fish  until  they  are  able  to  fly.  The  excreta  from  the  old 
and  the  young  birds,  feathers,  and  the  remains  of  the  young  birds 
that  die,  all  go  to  make  up  guano.     As  this  region  is  practically 

1  .American  Fertilizer. 
5 


50  FERTILITV   AXD   FERTILIZER    HINTS 

rainless  and  has  a  dry  hot  temperature,  these  remains  dry  out 
rapidly  and  are  preserved  without  much  loss  of  phosphoric  acid 
or  nitrogen.  There  is  some  loss  of  nitrogen  in  these  Pe- 
ruvian guanos  due  to  the  formation  of  ammonium  carbonate, 
a  volatile  form,  and  to  leaching  by  occasional  rains.  However, 
these  deposits  have  been  the  best  nitrogenous  guanos  in  the  world. 
There  are  deposits  in  other  parts  of  South  America,  West  Indies, 
Africa,  Australia,  Asia,  and  the  islands  of  the  Pacific,  but  the 
Peruvian  deposits  are  the  most  notable.  There  is  a  wide  differ- 
ence  in  the  composition  of  guanos.  Tn  Peru,  guano  from  the 
same  island  shows  variation  in  chemical  composition,  while  guano 
from  different  islands  shows  even  a  greater  variation.  The  old- 
est deposits  usually  contain  less  nitrogen  and  more  phosphoric 
acid  than  the  more  recent.  In  a  wet,  damp  climate,  fermenta- 
tion, aided  by  the  presence  of  moisture,  destroys  all  or  most  of 
the  organic  matter  driving  off  the  nitrogen  as  ammonium  carbo- 
nate. Soluble  phosphoric  acid  is  also  lost  in  such  regions. 
Therefore  it  is  easy  to  understand  the  wide  differences  in  the 
composition  of  these  deposits. 

Guanos  range  from  rich  nitrogenous  deposits  to  phosphatic  de- 
posits which  only  contain  traces  of  nitrogen  and  considerable 
amounts  of  phosphate  of  lime.  There  are  therefore  two  classes 
of  guanos,  namely,  nitrogenous  and  phosphatic.  The  phosphatic 
guanos  will  be  discussed  under  phosphates. 

Formerly  guano  was  used  more  extensively  in  the  United  States 
but  most  of  the  nitrogenous  deposits  have  been  exhausted  so  that 
the  importations  are  rather  decreasing  from  year  to  year.  There 
were  16,155  tons  imported  from  Peru  in  1905  and  5.500  tons  in 
1909.^ 

The  nitrogen  in  guanos  is  present  in  different  forms.  Some 
of  it  is  as  nitrates,  some  as  ammonia  and  some  as  organic  nitro- 
gen. The  presence  of  these  various  forms  makes  the  nitrogen- 
ous guanos  valuable  because  they  supply  plant  food  during  the 
whole  growing  season.* 

In  Mexico  there  are  deposits  of  bat  guano,  many  of  which  are 
good  nitrogenous  fertilizers,  but  they  are  not  being  worked  be- 

•  1910  American  Fertilizer  Handbook. 


HIGTI    GRADE    NITROGENOUS   FERTILIZER    MATERIALS  57 

cause  of  poor  transportation  facilities.  There  are  also  deposits 
of  bat  guano  in  Texas.  The  bat  guanos  are  not  as  a  rule  as 
valuable  as  the  high  grade  nitrogenous  Peruvian  guanos.* 

Ammonium  sulphate  is  unlike  the  organic  compounds  as  it  is 
not  a  natural  product  but  a  manufacturing  by-product.  When 
pure  it  is  a  white  crystalline  salt  but  sometimes  foreign  substances 
become  mixed  with  it,  in  the  course  of  manufacture,  which  causes 
it  to  be  grey,  yellow,  or  blue.  It  is  soluble  in  water  and  vola- 
tile, that  is,  it  will  pass  off  as  gas  when  strongly  heated  over  a 
flame.  It  is  derived  from  the  distillation  of  coal  in  the  manu- 
facture of  gas ;  from  the  distillation  of  bones  in  the  manufacture 
of  bone-black;  and  from  the  manufacture  of  coke  from  coal. 
Coal  was  formed  from  vegetable  matter  and  most  coals  average 
about  1.8  per  cent,  nitrogen.  When  coal  is  heated,  as  in  the 
manufacture  of  gas  or  coke,  about  ji  of  the  nitrogen  as  am- 
monia is  driven  off  and  this  ammonia  may  be  saved  by  washing 
it  in  water  in  special  apparatus.  The  solution  thus  formed  is 
then  distilled  into  sulphuric  acid,  concentrated  and  the  crystals  of 
sulphate  of  ammonia  separate  out  on  standing.  Bones  contain 
about  3  to  4.5  per  cent,  nitrogen  and  the  nitrogen  as  ammonia 
is  recovered  in  a  similar  way  as  in  distilling  coal  or  coke,  when 
they  are  subjected  to  dry  distillation  by  heat,  as  may  be  practiced 
in   the   manufacture   of   bone-black.* 

Composition  and  Availability. — Sulphate  of  ammonia  when  pure 
contains  21.2  per  cent,  nitrogen  but  the  commercial  article  usually 
runs  about  20  per  cent.  It  is  in  a  form  very  suitable  for  distri- 
bution in  the  soil  and  is  readily  converted  into  available  plant 
food.  It  is  more  available  than  the  organic  forms.  It  is  a  quick 
acting  fertilizer  and  suitable  therefore  for  quick  returns  in  crop 
production,  an  especial  advantage  for  truckers  and  market  gard- 
eners.    It  is  sometimes  substituted  for  nitrate  of  soda. 

As  it  is  readily  soluble  in  water  it  should  be  used  sparingly,  and 
frequent  small  applications  are  more  effective  than  large  amounts 
applied  at  long  intervals.  A  continued  use  of  it  may  cause  the 
soil  to  become  acid  because  of  the  sulphates  left  in  the  soil  after 
the  nitrogen  is  given  up.* 


58  FERTILITY  AND  FERTILIZER   HINTS 

Nitrate  of  Soda. — This  is  a  white  or  yellow  or  pink  crystalline 
salt.  The  nitrogen  in  nitrate  of  soda  is  in  a  form  that  can  be 
used  by  plants  without  undergoing  any  change.  Nitrate  of  soda 
is  the  highest  in  point  of  availability  of  any  of  the  nitrogenous 
fertilizer  materials.  It  induces  roots  to  grow  deep.  The  ni- 
trate diffuses  into  the  subsoil  and  the  plants  send  down  their  roots 
for  it.  This  is  indeed  of  great  benefit  because  it  enables  the  plant 
to  better  stand  dry  spells  and  it  increases  the  area  of  plant  food 
supply. 

It  is  found  in  extensive  deposits  on  the  west  coast  of  Chile 
and  is  often  called  Chile  saltpeter.  The  entire  deposits  are  found 
in  layers  sometimes  6  feet  thick,  about  2  to  10  feet  below  the 
surface,  and  are  blasted  out  and  treated  to  rid  the  product  of 
impurities.* 

Composition  and  Properties. — Nitrate  of  soda  contains  15  to 
16  per  cent,  nitrogen  and  the  average  product  found  on  the 
American  market  contains  15.3  per  cent,  nitrogen.  It  is  very 
soluble  in  water  and  therefore  it  should  be  supplied  in  small 
quantities  frequently  to  prevent  losing  it  by  leaching.  It  should 
be  kept  in  dry  storage  as  it  absorbs  water  and  is  liable  to  liquefy 
It  is  hard  to  distribute  evenly  on  the  soil  unless  it  is  mixed  with 
earth  or  some  other  material.  On  account  of  its  caustic  action 
it  should  be  applied  around  the  plants  and  not  on  them  as  it 
spots  green  vegetation.  It  should  be  kept  away  from  live-stock 
as  it  is  poisonous.  Acid  phosphates  when  damp  should  not  be 
mixed  with  nitrate  of  soda  as  nitrogen  is  lost.  The  acid  attacks 
the  nitrate  of  soda  liberating  the  nitrogen.* 

The  utilization  of  nitrogen  from  the  air  by  artificially  uniting 
and  fixing  it  with  other  elements  to  form  compounds  that  could 
compete  with  the  other  nitrogenous  fertilizer  materials  has  at- 
tracted the  attention  of  chemists  and  investigators  for  many  years. 
It  seems  that  at  last  the  problem  has  been  solved  and  it  is  now 
only  a  matter  of  a  short  time  when  the  present  modes  of  manu- 
facturing artificial  nitrogen  compounds  will  be  so  perfected  that 
we  will  not  be  forced  to  worry  about  the  future  supply  of  this 
important  element.     There  are  two  of  these  artificial  nitrogenous 


HIGH    GRADli    NITROGEXOUS    FERTILIZER    MATERIALS  59 

compounds  being  sold  to-day,  namely,  calcium  nitrate  and  calcium 
cyanamid. 

Calcium  nitrate  sometimes  called  lime  nitrogen  is  manufactured, 
with  cheaj)  water-power,  in  Notodden,  Norway.  It  contains 
about  13  per  cent,  of  nitrogen  and  can  be  sold  at  a  profit  for  $40 
per  ton,  which  is  equivalent  to  nitrate  of  soda  at  about  $50  per 
ton.  Recent  experiments  show  it  to  be  as  valuable  as  nitrate 
of  soda  in  crop  producing  power.* 

Calcium  cyanamid  is  a  grey  black  crystalline  powder.  It  is 
made  from  limestone,  coke  and  nitrogen  gas  with  the  aid  of 
the  electric  furnace.  When  calcium  cyanamid  was  first  placed 
upon  -the  market  it  contained  small  quantities  of  substances  in- 
jurious to  young  plants,  and  the  manufacturers  now  claim  to 
put  out  a  product  in  which  these  poisonous  materials  are  absent. 
It  carries  17  to  20  per  cent,  of  nitrogen.* 

Properties. — About  80  per  cent,  of  the  nitrogen  in  the  improved 
cyanamid  is  as  cyanamid  and  the  remaining  20  per  cent,  as  ni- 
trate. Calcium  cyanamid  contains  about  20  per  cent,  of  free  lime 
which  absorbs  water  and  carbonic  acid  gas  from  the  air,  causing 
the  lime  to  slake  and  the  product  to  decompose  so  that  ammonia 
is  formed.  This  ammonia  is  not  lost  to  any  great  extent  when 
the  product  is  kept  in  bags,  but  if  it  is  exposed  in  a  loose  pile  the 
loss  may  be  appreciable.  Calcium  cyanamid  is  soluble  in  water 
and  when  steam  is  introduced  into  it  ammonia  is  driven  off.  In 
the  soil  the  ammonia  is  given  off  by  the  action  of  water  and 
soil  micro-organisms.     The  action  with  water  is : 

CaCN^  4-  3H,0  =  CaCOs  -f  2NH3. 

Fertilizing  Value. — Experiments  show  that  this  product  has 
about  the  same  fertilizing  value  as  ammonium  sulphate  on  most 
soils.  It  is  therefore  highly  available.  It  would  no  doubt  show 
to  good  advantage  on  soils  deficient  in  lime.  Care  should  be 
exercised  in  its  application.  When  the  product  contains  injurious 
substances  it  is  liable  to  injure  seedlings  and  it  is  safe  practice 
to  apply  it  sometime  before  the  seed  is  planted.  It  is  thought 
to  be  injurious  when  used  as  a  top  dressing  but  this  point  has 
not  been  thoroughly  proved.  Should  the  '"Improved  Cyanamid" 
be  free  from  injurious  substances  it  will  prove  a  much  more  de- 
sirable fertilizer.* 


CHAPTER  VI. 


LOW  GRADE  NITROGENOUS  MATERIALS  AND  FUNCTIONS  OF 
NITROGEN. 

The  nitrogenous  substances  discussed  in  the  previous  chapter 
are  all  considered  high  class  and  valuable  standard  materials. 
Some  of  them  as  the  mineral  compounds  are  immediately  or  al- 
most immediately  available,  while  the  organic  materials,  both 
animal  and  vegetable,  vary  in  their  degree  of  availability,  but 
stay  with  the  crop  during  the  whole  or  the  greater  part  of  the 
season. 

The  high  prices  of  these  desirable  and  valuable  nitrogenous 
materials  have  caused  some  of  the  manufacturers  of  commercial 
fertilizers  to  seek  and  use  cheaper  sources  of  nitrogen.  Many 
of  these  cheaper  materials,  to  be  sure,  are  rich  in  nitrogen  but 
really  of  little  value  as  the  nitrogen  is  present  in  such  forms 
as  to  be  inert  or  else  too  slow  acting  to  stimulate  plant  growth. 
Many  of  these  low  grade  nitrogenous  waste  products  are  im- 
ported from  foreign  countries  yet  we  produce  our  share  of  them 
in  this  country.  They  are  made  up  of  wastes  from  the  manu- 
facture of  silk,  wool,  feathers,  combs,  hair,  skins,  sugar  and 
some  few  are  derived  from  vegetable  sources.  The  materials 
most  commonly  used  will  be  discussed. 

Raw  Leather  Meal. — This  product  contains  about  8  per  cent, 
nitrogen  which  is  in  a  form  that  is  very  slowly  utilized  by  plants  ;  it 
may  remain  in  the  soil  for  two  or  three  years  before  decaying.  It 
takes  such  a  Jong  time  for  it  to  decompose  that  it  has  not  much 
value  for  fertilizing  purposes.  One  of  the  objects  in  the  treat- 
ment of  leather  is  to  prevent  its  decay  and  for  this  reason  raw 
leather  may  remain  in  the  soil  for  a  very  long  time  before  under- 
going any  change.  This  material  is  sold  varying  in  the  degree 
of  fineness  from  a  dust  to  coarse  particles.  If  it  is  ever  used  it 
should  be  powdered.     At  best  it  is  a  tough  material. 

Dissolved  leather,  sometimes  called  treated  leather  or  extracted 
leather,  is  made  in  Belgium.  The  raw  leather  is  roasted  and  very 
finely  ground  and  treated  with  superheated  steam  which  removes 


LOW    GRADE    NITROGENOUS    MATERIALS,    ETC.  6l 

most  of  the  tannic  acid.  It  is  then  acidulated  with  sulphuric  acid 
to  fix  the  nitrogen  and  render  it  more  available.  This  material 
is  being  used  by  the  manufacturers  in  the  United  States  to  quite 
a  considerable  extent  because  it  is  cheaper  than  the  more  desirable 
nitrogenous  materials  per  unit  of  nitrogen.  This  product  con- 
tains about  8  per  cent,  nitrogen  and  is  more  valuable  than  raw 
leather. 

Feather  waste  and  various  skin  wastes  are  also  saved  for  fer- 
tilizing purposes. 

Hair  and  fur  waste  is  rich  in  nitrogen.  It  is  unsuitable  as 
fertilizer  because  it  is  so  slowly  decayed.  When  properly  treated 
with-sulphuric  acid  and  rendered  assimilative  for  plants  it  is  more 
valuable.     Hair  to  a  limited  extent  is  often  found  in  tankage. 

Mora  meal  is  a  vegetable  product,  brown  in  color,  which  is  im- 
ported from  Europe.  The  mora  seed,  which  are  grown  in  India 
and  probably  other  tropical  countries,  are  sent  to  Europe  where 
they  are  subjected  to  pressure  and  the  oil  extracted.  The  re- 
maining pomace  is  ground  and  sold  as  mora  meal.  This  product 
has  been  used  for  the  past  nine  years  in  the  United  States  and 
the  consumption  has  increased  every  year. 

It  carries  about  2.5  per  cent,  of  nitrogen  which  is  of  low  avail- 
ability. It  is  not  sold  with  any  guarantee  of  nitrogen,  phosphoric 
acid  and  potash,  but  on  a  flat  basis.  It  is  used  by  manufacturers 
of  commercial  fertilizers  principally  as  a  dryer  and  filler.  It  is 
good  for  both  of  these  purposes  because  it  is  an  excellent  ab- 
sorbent and  bulky. 

Beet  Refuse. — This  compound  is  a  grey  black  powdery  sub- 
stance. It  contains  from  5  to  7  per  cent,  nitrogen  and  about 
0.5  to  I  per  cent,  potash.  One  manufacturer  used  this  compound 
in  some  of  his  mixtures  because  he  believed  it  would  kill  in- 
sects in  the  soil.  He  believed  this  because  of  the  presence  of 
sulpho-cyanic  acid  in  this  compound. 

Scutch. — This  is  a  by-product  or  waste  product  in  the  manu- 
facture of  glue  and  the  dressing  of  skins.  It  is  manufactured  in 
England  and  contains  about  7  per  cent  nitrogen. 

Horn  and  hoof  meal,  horn  shavings,  etc.,  are  products  obtained 
from  slaughtering  houses  or  by-products  in  the  manufacture  of 


62  FERTILITY    AND   I'ERTIUZER    HINTS 

combs  and  similar  articles.  In  the  raw  state  they  are  extremely 
hard  to  grind  and  are  not  valuable  in  this  form  because  they 
decay  too  slowly  to  supply  plant  food  with  any  degree  of  rapidity. 


Hi 

gpiii 

^aSa^^BI^^^I 

H 

^i| 

li '      G( 

m 

m 

W^ 

9 

B^         '' " 

^^M^ 

r        '^,.»^^^^^^ 

Fig.  b.—\  stock  yards  scene  where  tankage,  blood,  liorn  and  hoof  meal  and 
similar  fertilizer  products  are  saved. 

When  steamed  and  pulverized  they  become  high  grade  products 
as  mentioned  in  the  previous  chapter. 

Wool  waste,  shoddies,  etc.,  taken  collectively  is  the  term  ap- 
plied to  any  waste  from  silk  or  wool  manufacturing  which  is  no 
longer  profitable  for  making  cloth.  It  is  slow  to  decay  and  is 
rather  undesirable  as  fertilizer.  It  is  often  coarse  and  bulky  and 
hard  to  mix  in  a  manufactured  fertilizer  or  to  distribute  evenly 
when  applied  to  the  soil.* 

It  is  sometimes  treated  with  superheated  steam,  the  liquid 
evaporated  to  dryness  and  the  product  ground,  or  else  it  may  be 
acidulated  with   sulphuric  acid   for  a  long  time    (2  months)    to 


LOW    GRADK    NITROGKNOUS    MATERIALS,    ETC.  63 

render  the  nitrogen  available.  When  treated  by  either  of  the 
above  methods,  it  is  known  as  dissolved  wool,  shoddy,  etc.,  and 
is  of  course  more  valuable  than  the  raw  products  from  which 
it  is  made. 

Garbage  Tankage. — Many  of  the  large  cities  have  plants  where 
the  garbage  is  accumulated.  It  is  dried,  or  charred,  or  steamed, 
or  extracted  and  the  treated  product  is  sold  as  garbage  tankage. 
This  material  contains  about  2  per  cent,  of  nitrogen  which  is  in 
a  form  that  is  slowly  assimilated  by  plants.  It  is  not  a  valuable 
fertilizer.* 

Dried  peat,  sometimes  called  dried  muck,  is  used  principally  by 
the  'manufacturers  because  of  its  excellent  drying  properties. 
The  use  of  it  enables  the  manufacturer  to  put  out  a  fertilizer 
in  a  fine  mechanical  condition  which  may  be  distributed  evenly 
on  the  soil.  This  material  varies  in  composition,  depending  on 
the  amount  of  vegetable  and  mineral  matter  present,  but  may  be 
considered  as  averaging  1.5  to  2  per  cent,  of  nitrogen. 

Availability  of  Nitrogenous  Fertilizer  Materials. — The  only  cor- 
rect way  to  determine  the  value  of  any  nitrogenous  substance  is 
by  running  experiments  with  growing  plants.  The  high  grade 
products  as  nitrate  of  soda,  sulphate  of  ammonia,  dried  blood, 
cotton-seed  meal,  linseed  meal,  castor  pomace,  dry  ground  fish, 
tankage,  ground  bone,  steamed  horn  and  hoof  meal,  etc.,  have 
been  tested  by  field  experiments  to  determine  their  crop  produc- 
ing power.  Laboratory  methods  have  been  introduced  to  corre- 
spond as  near  as  possible  with  the  field  results. 

The  availability  of  nitrate  of  soda  is  always  taken  as  100  and 
the  availability  of  the  other  materials  is  based  on  the  results 
secured  when  compared  to  nitrate  of  soda.  Should  nitrate  of 
soda  give  an  increased  yield  of  500  pounds  per  acre  for  a  crop, 
the  yield  of  a  nitrogenous  fertilizer  of  75  per  cent,  availability 
would  give  an  increase  of  375  pounds,  etc. 

Not  Always  Possible  to  Run  Field  Experiments. — To  conduct 
field  experiments  is  often  impossible,  because  of  the  great  expense, 
the  long  time  required,  the  difference  in  soils,  the  variation  in 
seasons,  the  ability  of  the  various  crops  for  securing  plant  food, 
the  association  with  other  fertilizing  materials  containing  phos- 


64  FERTILITY  AND  FERTILITY  HINTS 

phoric  acid,  potash,  lime,  etc.,  so  that  much  of  our  information 
on  the  low  grade  products  has  been  worked  out  in  the  laboratory 
by  chemical  methods.  These  methods  are  not  entirely  satisfac- 
tory but  indicate  to  a  great  extent  the  relative  values  of  nitrog- 
enous fertilizers,  as  to  whether  they  are  high  grade,  medium 
grade  or  low  grade.* 

Value  of  Low  Grade  Materials. — Raw  leather,  wool  waste, 
shoddy,  hair,  etc.,  may  be  rendered  fairly  available  as  plant  food 
by  special  treatment,  but  such  treatment  usually  is  expensive 
and  the  market  value  does  not  always  permit  it.  The  standard 
high  grade  materials  are  always  to  be  preferred  and  these  low 
grade  wastes  cannot  be  sold  unless  they  are  much  cheaper.  Hence 
these  low  grade  substances  are  usually  only  partially  treated  or 
not  at  all,  so  that  they  have  very  little  value  as  fertilizer  and 
the  use  of  them  is  liable  to  cause  disappointment  and  poor  yields. 
They  are  not  always  sold  alone  but  are  sometimes  mixed  together. 
The  writer  has  examined  a  product  imported  from  Belgium  and 
sold  as  Foreign  Imported  Tankage  which  was  made  up  of  shoddy, 
wool  waste,  hair,  and  leather  and  was  only  partially  treated. 
Most  of  the  material  was  in  the  raw  state  and  in  poor  mechanical 
condition ;  chemical  methods  showed  it  to  be  poor  plant  food. 
This  material  contained  about  7  per  cent,  nitrogen  with  traces  of 
phosphoric  acid.  Should  any  of  these  low  grade  substances  be 
used,  the  purchaser  should  demand  that  they  be  powdered,  or 
ground  very  fine,  in  order  to  give  the  soil  organisms  a  better 
chance  to  decompose  them.  The  purchaser  should  not  expect  to 
get  quick  results  with  many  of  these  wastes  as  some  of  them, 
particularly  the  raw  leather,  may  remain  in  the  ground  for  two 
or  three  years  without  any  apparent  change. 

The  Use  of  Low  Grade  Materials  is  Increasing. — The  use  of  these 
low  grade  materials  seems  to  be  increasing  and  many  manufac- 
turers are  using  them  in  their  low  grade  cheap  fertilizers  which 
carry  low  percentages  of  nitrogen,  to  a  greater  or  less  extent. 
The  writer  believes  that  some  of  these  materials  have  no  doubt 
been  misrepresented  to  the  manufacturers  or  else  they  would  not 
use  them.  In  order  to  insure  future  business  they  endeavor  to 
put  out  fertilizers  that  will  give  good  crop  returns,  and  by  satisfy- 


LOW    GRADE    NITROGENOUS    MATERIALS,    ETC.  65 

ing  their  formulas  with  much  of  this  class  of  material  the  poor 
crop  returns  will  surely  hurt  them  in  repeating  orders. 

Some  of  these  materials  are  said  to  be  used  as  dryers  by  the 
manufacturers  (peat  and  mora  meal  for  example)  but  analyses 
of  fertilizers  containing  them  often  show  that  the  manufacturers 
counted  the  nitrogen  content  in  making  the  fertilizers.  Peat  to  be 
sure  is  a  valuable  filler  for  fertilizers  as  in  addition  to  its  drying 
qualities  it  contains  about  30  per  cent,  of  humus,  but  its  nitrogen 
is  not  readily  available  and  fertilizers  containing  it  should  have 
their  guarantees  satisfied  by  the  use  of  more  available  substances. 

The  Nitrogenous  Materials  to  Use. — We  have  learned  that  most 
plants  assimilate  nitrogen  from  the  soil  as  nitrate  and  occasion- 
ally as  ammonia.  We  also  know  that  certain  organisms  in  the 
soil  convert  the  nitrogen  from  organic  sources  into  ammonia 
and  from  ammonia  into  nitrates.  Therefore  it  is  reasonable  to 
suppose  that  substances  containing  nitrogen  as  nitrates  are  to  be 
preferred  for  immediate  results  in  plant  growth.  As  ammonia 
is  converted  to  nitrates  in  the  soil,  materials  containing  nitrogen 
as  ammonia,  as  ammonium  sulphate  for  example,  are  less  active 
than  nitrate  of  soda.  Again,  nitrogen  from  organic  sources  is 
less  active  than  from  substances  containing  nitrogen  as  nitrates 
or  ammonia,  as  organic  nitrogen  must  be  changed  to  ammonia 
and  nitrates  before  being  usable,  and  we  would  use  materials 
furnishing  this  form  of  nitrogen  for  slower  and  more  lasting 
results.  We  have  seen  that  the  nitrogen  from  organic  products 
varies  a  great  deal  in  the  power  of  giving  up  or  holding  nitrogen. 
Dried  blood  and  cotton-seed  meal,  for  example,  give  up  nitrogen 
quicker  than  tankage  and  dry  ground  fish,  and  these  latter  sub- 
stances do  not  hold  nitrogen  as  long  as  leather  preparations  and 
wool  waste.  Therefore  in  selecting  the  proper  nitrogenous  ma- 
terial or  materials  to  use  we  must  consider  the  condition  of  the 
soil,  climate,  locality,  kind  of  crop,  etc. 

For  Immediate  Results. — Should  immediate  results  be  desired, 
applications  of  nitrate  of  soda,  sulphate  of  ammonia,  lime  nitrate, 
or  calcium  cyanamid  should  serve  the  purpose.  The  locality  may 
prevent  the  use  of  organic  substances  as  a  certain  amount  of  heat 
(37°  F.)   is  required  for  the  soil  organisms  to  convert  organic 


66  FERTILITY   AND   FERTILIZER    HINTS 

nitrogen  into  nitrates.  A  wet  season  checks  nitrification  and 
hence  nitrate  of  soda  and  sulphate  of  ammonia  should  give  better 
results  than  the  organic  materials. 

For  Soils  Well  Supplied  and  Long  Growing  Crops. — Should  the 
soil  have  a  sufficient  natural  supply  of  organic  nitrogen  as  from 
some  leguminous  crop  plowed  under,  etc.,  perhaps  no  organic 
nitrogenous  material  should  be  applied  and  a  small  application 
of  some  one  of  the  mineral  salts  may  suffice  to  give  the  crop  a 
start.  If  the  crop  is  a  long  growing  one,  an  organic  product 
may  prove  best,  as  it  gives  up  its  nitrogen  in  smaller  amounts  and 
more  slowly  than  the  chemicals  and  will  thus  stay  with  the  crop 
the  whole  season.  Mixtures  of  minerals  and  organic  materials 
may  sometimes  be  best  so  as  to  enable  the  plant  to  get  a  quick 
start  by  supplying  immediate  food  and  when  this  supply  is  ex- 
hausted, to  furnish  nourishment  from  the  organic  sources  for 
'the  remainder  of  the  season.  The  fertilizer  manufacturers  often 
use  two  or  three  dififerent  nitrogenous  substances  of  different 
forms,  as  nitrate  of  soda,  sulphate  of  ammonia  and  cotton-seed 
meal,  in  their  fertilizers  to  allow  the  plant  a  continual  supply 
of  available  nitrogen.  Mixtures  of  organic  materials  of  different 
availabilities  may  make  excellent  combinations  for  certain  crops. 

For  Large  Crops  and  Building  up  the  Soil. — Should  a  large  crop 
be  desired  the  chemicals  and  the  active  organic  substances  would 
perhaps  be  preferable,  but  should  the  building  up  of  the  soil  for 
some  future  crop  be  wished,  the  less  active  organic  materials 
would  prove  more  valuable  than  nitrate  of  soda,  ammonium  sul- 
phate, lime  nitrate,  calcium  cyanamid,  dried  blood,  cotton-seed 
meal,  etc.,  as  these  materials  are  all  changed  to  the  nitrate  form, 
except  nitrate  of  soda  which  is  already  in  this  form,  either  im- 
mediately or  during  the  season  and  would  in  all  probability  be 
lost  because  nitrates  do  not  become  fixed  in  the  soil  and  are  readi- 
ly washed  away  by  heavy  rains.  The  nitrogen  in  organic  ma- 
terials is  not  soluble  in  water  to  any  great  extent  as  is  the  case 
with  nitrate  of  soda,  sulphate  of  ammonia,  lime  nitrate  and  cal- 
cium cyanamid  so  that  the  losses  by  leaching  of  the  former  sub- 
stances are  not  considerable  as  compared  to  those  of  the  latter. 

It  is  evident  then  that  the   farmer  should  select  those  sub- 


LOW    GRADE    NITROGENOUS    MATERIALS.     ETC. 


^7 


stances  that  will  give  the  best  results  for  his  conditions  and  not 
purchase  nitrogenous  fertilizer  that  some  neighbor  recommends 


Fig.  7.— A  good  crop  of  hay,  the  result  of  judicious  soil  management. 

who  secured  good  crops  with  an  entirely  difTerent  crop  and  soil, 
etc.* 

Functions  of  Nitrogen. — Nitrogen  increases  growth  and  defers 
maturity.  In  a  certain  parish  in  Louisiana  where  the  people  were 
ignorant  along  fertilizing  lines,  cotton-seed  meal  was  the  only 
fertilizer  known  to  them.  So  year  after  year  they  applied  this 
fertilizer  to  their  cotton.  For  the  last  three  years  that  they 
practiced  this,  they  produced  excellent  large  cotton  plants  but 
the  crop  did  not  mature  well  or  produce  scarcely  any  cotton. 
The  people  could  not  understand  it.  They  did  not  know  that 
cotton-seed  meal  was  a  nitrogenous  fertilizer  nor  did  they  know 
that  nitrogen  produced  growth.  The  Experiment  Station  was 
called  upon  to  investigate  the  trouble  and  as  the  soil  was  natur- 
ally rich  in  potash,  applications  of  acid  phosphate  corrected  the 
condition.  The  above  example  shows  the  results  of  an  excess 
of  nitrogen  in  producing  growth  and  deferring  maturity. 


68  FERTILITY   AND  FERTILIZER   HINTS 

When  excessive  nitrogen  is  applied  to  potatoes  it  produces  a 
vigorous  growth  of  vines  but  very  few  tubers  are  formed.  Should 
an  excess  of  nitrogen  be  suppHed  the  small  grain  crops  it  would 
cause  them  to  lodge  and  produce  grain  of  inferior  quality  and 
the  excess  of  the  weight  of  the  crop  to  the  weight  of  the  grain 
would  be  high.  Excessive  nitrogen  retards  the  formation  of 
fruit.  It  produces  growth  of  wood  and  leaves  when  the  fruit 
should  be  forming. 

When  nitrogen  is  lacking  in  the  soil  the  plants  do  not  grow 
so  high  as  when  the  supply  is  sufficient.  With  crops  grown  on 
such  soils  the  proportion  of  grain  or  seed  to  the  weight  of  the 
crop  is  high.  No  matter  how  much  phosphoric  acid  and  potash 
there  may  be  in  the  soil  the  crops  can  only  use  quantities  in 
proportion  to  the  growth  of  the  plants,  and  the  growth  of  plants 
will  be  in  proportion  to  the  nitrogen  supply. 

Generally  speaking  an  application  of  a  nitrogenous  fertilizer 
will  produce  increased  yields  without  the  application  of  potash 
and  with  an  occasional  supply  of  phosphoric  acid.  The  nitrogen 
produces  a  better  leaf  development,  a  better  growth,  the  color  of 
crops  become  a  darker  green,  and  the  crop  matures  later.  Often 
the  supplying  of  nitrogen  alone  will  increase  yields  to  such  an 
extent  that  farmers  may  overate  the  value  of  this  constituent. 
On  soils  that  are  deficient  in  organic  matter,  that  have  been 
continually  cropped,  the  need  of  nitrogen  is  generally  greater  than 
phosphoric  acid  and  potash.* 

Market  gardeners  often  take  advantage  of  the  power  of  ni- 
trogen in  the  growing  of  lettuce  and  similar  vegetables.  Vege- 
tables grown  on  soils  more  than  amply  supplied  with  nitrogen  pro- 
duce more  delicate  and  tender  vegetables,  especially  lettuce  and 
cabbage,  but  they  do  not  stand  shipping  so  well ;  although  better 
for  immediate  consumption  than  vegetables  grown  on  average 
soils  they  wilt  and  spoil  quickly  and  are  not  popular  with  the 
commission  houses.  The  cell  walls  and  tissues  are  not  so  strong 
with  crops  grown  on  excessive  nitrogen  as  when  not. 

Excessive  Nitrogen  Invites  Diseases. — Crops  grown  on  soils  that 
have  excessive  nitrogen  are  more  susceptible  to  plant  diseases 
than  on  average  soils.     This  may  be  noticed  to  a  limited  extent 


LOW    GRADU    NITROGENOUS    MATERIALS,     ETC.  69 

with  oats  and  wheat.  When  the  season  is  especially  favorable 
to  the  production  of  nitrates  in  the  soil  during  the  growing  period 
or  when  oats  and  wheat  are  grown  on  rich  nitrogenous  soils  rust 
is  more  prevalent  than  usual.  Plant  diseases  due  to  excessive 
nitrogen  are  perhaps  more  noticeable  with  crops  grown  under 
glass  than  outside.  Most  of  the  soils  that  are  used  in  hothouses 
are  very  rich  in  nitrogen  and  the  high  temperatures  kept  renders 
nitrification  very  rapid.  The  color  of  the  leaves  of  hothouse 
crops  becomes  a  darker  green  when  excessive  nitrogen  is  present ; 
the  leaves  become  tender  and  thin  and  seem  to  be  easily  attacked 
by  certain  fungi  unless  extra  precautions  are  taken.  Cucum- 
bers are  especially  susceptible  to  disease  in  the  presence  of  ex- 
cessive nitrogen. 


CHAPTER  VII. 


PHOSPHATES. 


Phosphates  are  those  materials  that  contain  phosphoric  acid. 
The  phosphates  occur  as  phosphate  of  Hme,  iron  and  alumina, 
in  which  compounds  the  phosphoric  acid  is  united  with  lime, 
iron  and  alumina  respectively.  Since  the  phosphoric  acid  in  fer- 
tilizers is  derived  mainly  from  phosphate  of  lime  we  will  limit 
our  treatment  of  the  subject  to  the  important  materials  compos- 
ing this  group. 

The  phosphates  of  lime  occur  as  organic,  organic  and  mineral, 
and  mineral  compounds. 

Bones. — The  chief  source  of  phosphoric  acid  from  the  organic 
phosphates  of  hme  are  bones.  The  composition  of  bones  is 
variable.  The  bones  from  old  mature  animals  are  richer  in  phos- 
phate of  lime  than  bones  from  young  animals.  Dififerent  bones 
from  the  same  animal  also  show  a  variable  composition,  as  the 
harder  more  compact  bones  are  richer  in  phosphate  of  lime  than 
the  softer,  porous  ones. 

Raw  Bone-Meal. — This  is  the  finely  ground  product  derived 
from  raw  bones  and  it  contains  all  the  constituents  of  thenii. 
It  carries  considerable  organic  matter  much  of  which  is  in  the 
form  of  fats,  which  makes  it  hard  to  grind  and  to  handle  on  the 
market.  The  presence  of  organic  matter  makes  it  objectionable. 
The  fatty  matter,  which  slowly  decomposes,  tends  to  make  this 
fertilizer  very  slowly  available  for  plant  food  and  so  it  is  called 
a  slow  acting  fertilizer.  Raw  bone-meal  usually  contains  about 
19  to  25  per  cent,  of  phosphoric  acid  and  2  to  4  per  cent,  of 
nitrogen,  with  an  average  of  22  per  cent,  of  phosphoric  acid 
and  3.5  per  cent,  of  nitrogen.* 

The  phosphates  are  sold  to  the  trade  on  the  basis  of  tri- 
calcium  phosphate  present.  To  convert  tricalcium  phosphate 
to  phosphoric  acid,  multiply  by  the  factor  0.4576  and  to  get  the 
equivalent  of  tricalcium  phosphate  from  a  given  percentage  of 
phosphoric  acid  multiply,  by  2.185. 

Steamed  Bone-Meal. — Most   of   the  bone   sold    for    fertilizing 


PHOSPHATES  71 

purposes  has  been  boiled  or  steamed  in  the  rendering  factories 
to  extract  the  fats  and  nitrogenous  compounds  which  are  used 
in  making  soap,  glue,  and  gelatine.  The  bones  are  then  ground 
or  pulverized  and  sold  as  steamed  bone-meal,  bone-meal  and  lx)ne- 
(lust.  This  product  is  variable  in  composition,  ranging  from  17.5 
to  29  per  cent,  of  phosphoric  acid  and  1.5  to  4.5  per  cent,  of 
nitrogen.  Good  clean  bone-meal  should  contain  at  least  2.5  per 
cent,  of  nitrogen  and  25  per  cent,  of  phosphoric  acid.  The 
treatment  of  the  raw  bones  affects  the  final  composition  of  the 
product  (steamed  bone-meal)  ;  the  boiling  or  steaming  reduces  the 
nitrogen  content  and  increases  the  phosphoric  acid. 

Steamed  bone-meal  is  a  more  quickly  available  fertilizer  than 
raw  bone-meal  and  is  therefore  better  for  most  crops. 

There  is  a  great  difference  in  the  steamed  bone-meals  put 
upon  the  market  not  only  in  the  composition  but  in  the  hardness 
of  the  product.  Steamed  bone-meal  from  some  factories  is  more 
porous  and  softer  than  from  others.  Some  factories  put  out  a 
product  that  crumbles  easily  while  others  sell  meal  that  is  ex- 
tremely hard.* 

Degree  of  Fineness. — The  bones  when  sold  for  fertilizing  pur- 
ix>ses  are  ground  fine  and  are  known  as  fine  ground  bone,  bone- 
meal,  bone-dust  and  bone-flour.  The  mechanical  condition  of 
fineness  does  not  affect  the  composition  but  increases  the  avail- 
ability of  the  product  for  plant  food.  Hence  the  finer  the  bones 
are  ground  the  more  valuable  they  are  as  quicker  acting  fertilizers. 
These  products  are  generally  valued  according  to  their  degree  of 
fineness  and  chemical  composition.  It  must  be  remembered  that 
all  bone-meals  give  up  their  plant  food  slowly  and  are  not  de- 
sirable for  immediate  results  in  the  production  of  crops.* 

Bone-Black. — In  the  manufacture  of  bone-black,  the  choicest 
bones  are  selected,  cleaned  and  dried.  They  are  then  put  in  air- 
tight vessels,  heated  and  distilled  until  all  the  organic  or  volatile 
matter  has  passed  off.  The  product  is  then  ground  to  a  coarse 
consistency  and  sold  to  the  sugar  refineries  for  clarifying  or  de- 
colorizing syrups  in  the  manufacture  of  white  table  sugar.  After 
it  has  served  its  usefulness  in  the  sugar  refineries  it  is  sold  for 
6 


72  FERTIUTY   AND  FERTILIZER   HINTS 

fertilizer.  It  contains  usually  about  30  per  cent,  of  phosphoric 
acid  in  the  form  of  phosphate  of  lime.  It  is  a  slow  acting- 
fertilizer  and  is  not  used  extensively  in  this  condition.* 

Bone-Ash. — When  bones  are  burned  the  remaining  product  is 
called  bone-ash.  It  is  not  manufactured  a  great  deal  in  this 
country  because  of  the  greater  value  of  bone-black.  It  is  an  ex- 
cellent fertilizer  and  the  only  shipments  received  to-day  come 
from  South  America  where  the  bones  are  burned  to  save  freight. 
In  burning  bones  the  nitrogen  is  driven  off,  so  that  bone-ash  is 
valuable  only  for  the  phosphoric  acid  it  contains.  It  varies  in 
phosphoric  acid  content  from  30  to  39  per  cent.  It  is  used  in 
some  countries  in  the  manufacture  of   fertilizers.* 

Bone  Tankage. — This  product  is  composed  entirely  of  animal 
matter.  It  is  the  refuse  from  slaughter  houses  and  rendering 
factories  and  consi.sts  of  meat,  bone,  etc.  (from  which  the  fat  has 
been  extracted),  and  sometimes  a  little  dried  blood.  There  are 
many  grades  of  tankage  put  upon  the  market.  Those  tankages 
coming  under  the  head  of  bone  tankage  contain  considerable  bone 
and  small  amounts  of  meat  and  sometimes  dried  blood.  The 
amount  of  phosphoric  acid  in  tankage  varies  with  the  bone  con- 
tent. The  more  bone  present  the  higher  is  the  percentage  of 
phosphoric  acid.  The  bone  tankages  range  from  11^2  per  cent, 
to  20  per  cent,  of  phosphoric  acid.  Those  tankages  falling  be- 
low 11^4  per  cent,  of  phosphoric  acid  are  discussed  under  the 
chapter  on  nitrogenous  fertilizer  materials.  The  phosphoric  acid 
in  bone  tankages  has  about  the  same  value  as  in  steamed  bone, 
since  both  of  these  products  are  steamed  or  boiled  to  extract  the 
fats,  etc.  The  bone  tankages  are  very  popular  among  farmers 
in  certain  sections  of  this  country. 

Dry  Ground  Fish. — This  is  also  an  organic  source  of  phosphoric 
acid  from  phosphate  of  lime.  The  phosphoric  acid  content  de- 
pends upon  the  amount  of  bones  present.  This  product  was  de- 
scribed with  the  fertilizer  materials  containing  nitrogen.  Suffice 
it  to  say  that  dry  ground  fish  carries  from  6  to  16  per  cent,  of 
phosphoric  acid. 


PIlOSPHATl'S  73 

Average  Composition  of  Organic  Phosphates  of  Lime. 


Raw  bone-meal 

Steamed  bone-meal  • 

Bone-black 

Bone-ash 

Bone  tankage 

Dry  ground  fish 


Phosphoric  acid 
Per  cent. 


Nitrogen 
Per  cent. 


22  I        3-5 

25  2.5 

30  

36  — 

r.5-20  I        4-6 

9  I       8.5 


The  phosphoric  acid  present  in  raw  bone-meal,  steamed  bone- 
meal,  bone  tankage,  bone-black,  bone-ash  and  dry  ground  fish 
is  insoluble  in  water  and  slowly  available  as  plant  food. 

Mineral  Phosphates. — These  occur  in  natural  beds  in  different 
parts  of  the  world.  According  to  Van  Horn  in  the  American 
Fertilizer,  the  known  phosphate  deposits  of  the  United  States  are 
distributed  principally  among  four  localities:  (i)  along  the 
west  coast  of  Florida,  running  back  20  to  25  miles  inland;  (2) 
along  the  coast  of  South  Carolina,  extending  6  to  20  miles  in- 
land;  (3)  in  central  Tennessee;  and  (4)  in  an  area  comprising 
southeastern  Idaho,  southwestern  Wyoming,  and  northeastern 
Utah.  In  addition  to  these  areas,  some  deposits  occur  in  north- 
central  Arkansas,  along  the  Georgia-Florida  State  line,  and  in 
North  Carolina,  Alabama,  Mississippi,  and  Nevada,  but  these  are 
mainly  of  low  grade  and  not  utilized  at  the  present  time.  The 
three  important  deposits  first  mentioned  have  been  worked  from 
ten  to  thirty  years ;  the  fourth  is  a  new  field  which  has  as  yet  had 
but  a  small  output.''' 

The  most  important  deposits  in  this  country  are  in  Florida, 
South  Carolina,  and  Tennessee  and  the  production  in  the 
United  States  amounts  to  over  two  million  long  tons  (2,240 
pounds)  a  year  while  that  of  the  remaining  countries  approxi- 
mates one  million  tons. 

South  Carolina  phosphates  were  first  put  upon  the  market  in 
1868.  There  are  two  kinds  of  phosphates  found  in  South  Caro- 
lina, namely,  the  land  and  river  phosphates.  The  land  phosphate 
IS  mined  from  the  land  and  is  known  as  land  rock,  while  the 
river  phosphate  is  obtained  by  dredging  rivers  and  is  called  river 


74  FERTILITY   AND  FERTILIZER   HINTS 

rock.  These  phosphates  occur  in  the  form  of  nodules  varying  in 
weight  from  a  fraction  of  an  ounce  to  more  than  a  ton. 

Whether  the  rocks  are  mined  or  dredged,  they  are  washed 
free  from  the  clay  and  other  adhering  matter  and  dried, 
when  they  are  ready  for  shipment.  When  phosphate  rock 
is  ground  or  pulverized  it  is  known  as  floats  and  is 
used  in  this  form  in  the  middle  western  states  quite  extensively. 
The  land  rock  is  light  fawn  colored;  the  river  rock  is  black;  both 
are  very  hard.  The  South  Carolina  land  rock  averages  about  50 
per  cent,  tricalcium  phosphate,  which  is  equivalent  to  about  23 
per  cent,  of  phosphoric  acid,  and  the  river  rock  runs  about  50 
to  60  per  cent,  tricalcium  phosphate,  which  is  equivalent  to  23 
to  27.5  per  cent,  of  phosphoric  acid. 

Including  the  year  1908,  South  Carolina's  total  production  of 
phosphates  was  12,138,454  long  tons  of  rock,  of  which  about 
one-third  was  shipped  to  Europe.  The  discovery  of  the  Florida 
phosphates  decreased  the  exportation  of  those  from  South  Caro- 
lina, to  about  30,000  tons  annually,  because  the  Florida  phosphates 
that  are  exported  contain  more  phosphoric  acid  and  less  im- 
purities.* 

Florida  phosphates  occur  as  soft  phosphate,  pebble  phosphate 
and  boulder  or  hard  rock  phosphates.  The  soft  phosphate 
resembles  a  whitish  clay  and  generally  contains  50  to  60  per  cent, 
of  tricalcium  phosphate,  which  is  equivalent  to  23  to  27.5  per  cent, 
of  phosphoric  acid.  The  hard  rock  ranges  from  60  to  75  per 
cent,  of  tricalcium  phosphate,  which  is  equivalent  to  27.5  to  34.3 
per  cent,  of  phosphoric  acid,  although  many  samples  show  even  a 
higher  content  of  phosphoric  acid.  Most  all  of  the  high  grade 
phosphates  of  Florida  are  exported  to  Europe  where  they  find 
a  ready  market.  Florida  has  put  out  14,087,833  tons  of  phos- 
phate rock  from   1888  to  1908.* 

Tennessee  Phosphates. — These  are  perhaps  the  most  extensive 
deposits  in  the  United  States  that  are  being  worked.  Their  com- 
mercial importance  was  made  known  in  1893.  The  Tennessee 
phosphates  are  known  as  brown  rock,  blue  rock  and  white  rock. 
About  one-fourth  of  the  high  grade  Tennessee  phosphate  is  ship- 


\ 


PHOSPHATES  75 

ped  to  Europe  the  remainder  being  used  in  this  country.  The 
output  of  Tennessee  phosphate  has  amounted  to  5,315,422  tons 
from  1893  to  1908.  The  Tennessee  rock  phosphates  are  not  in 
favor  in  Europe  because  of  their  high  content  of  iron  and  alumina 
oxides,  which  run  from  2  to  4.5  per  cent. 

The  brown  rock  has  been  sold  more  than  the  blue  or  white 
rock.* 

Canadian  Apatite, — This  is  rock  where  the  phosphate  has  be- 
come crystalline  and  is  known  as  apatite  and  is  found  principally 
in  the  provinces  of  Ontario  and  Quebec.  It  is  not  mined  very 
extensively,  only  748  tons  being  produced  for  1907.  It  is  a 
variable  product  and  contains  impurities.  The  Canadian  apatite 
carries  from  75  to  90  per  cent,  of  tricalcium  phosphate,  which  is 
equivalent  to  34  to  41  per  cent,  of  phosphoric  acid.  Preparing 
Canadian  apatite  for  the  market  is  a  more  expensive  operation 
than  mining  the  American  phosphates.  Apatite  is  usually  con- 
sidered one  of  the  purest  forms  of  tricalcium  phosphate  for 
manufacturing  fertilizers.* 

Rodunda  Phosphate. — This  phosphate  is  found  on  the  Rodunda 
Island.  It  is  not  a  phosphate  of  lime  but  a  phosphate  of  iron 
and  alumina.  Although  the  per  cent,  of  phosphoric  acid  is  high, 
(20-38  per  cent.)  this  material  cannot  be  used  to  manufacture 
into  acid  phosphate  because  of  the  absence  of  lime.  The  gypsum 
(sulphate  of  lime)  formed  in  the  manufacture  of  acid  phosphate 
from  phosphate  of  lime  acts  as  a  drier.  Rodunda  phosphate  may 
be  used  for  crops  provided  it  is  well  pulverized  but  it  must  be 
considered  as  slow  acting.  This  product  is  sometimes  called 
iron  and  alumina  phosphate  rock. 

Basic  Slag. — This  is  known  by  several  names  as  iron  phosphate. 
Thomas  phosphate  powder,  odorless  phosphate,  and  phosphate 
slag.  When  phosphatic  iron  ores  are  used  for  the  manufacture  of 
steel  by  the  basic  process,  an  excess  of  lime  is  used  which  unites 
with  the  phosphoric  acid  and  iron  and  forms  a  product  known  as 
basic  slag.  There  is  not  much  of  this  product  manufactured  in 
this  country  but  the  production  is  large  in  England,  France  and 
Germany.     According   to    Wiley:     The   quantity   of   basic    slag 


'jd  FERTILITY  AND  FERTILIZER   HINTS 

manufactured  in  Germany  in  1893  was  750,000  tons;  in  England 
160,000;  in  France  115,000,  making  the  total  production  of 
central  Europe  about  1,000,000,  a  quantity  sufficient  to  fertilize 
nearly  5,000,000  acres.  During  the  year  1907,  it  is  estimated 
that  German  agriculture  made  use  of  from  1,500,000  to  1,600,000 
tons  of  basic  phosphate  slags.  The  total  output  of  basic  slag 
is  undoubtedly  not  far  from  2,000,000  tons.  The  total  produc- 
tion of  basic  slag  is  therefore  approximately  one-half  of  that  of 
crude  phosphates.^ 

This  product  is  sold  in  the  form  of  an  inpalpable  powder  which 
is  black  in  color.  The  phosphoric  acid  in  basic  slag  is  often  rated 
as  valuable  as  the  phosphoric  acid  in  bone-meal.  The  composi- 
tion of  this  product  is  variable  depending  on  the  amount  of  phos- 
phoric acid  in  the  iron  ore,  but  it  is  possible  to  obtain  this  pro- 
duct containing  23  per  cent,  of  phosphoric  acid,  but  the  lower 
grades  are  most  common.  It  averages  about  14.20  per  cent,  of 
phosphoric  acid.  On  account  of  the  large  amounts  of  iron  oxide 
present,  it  is  not  suitable  for  manufacturing  artificial  fertilizers.* 

Phosphatic  Guanos. — These  guanos  are  of  the  same  origin  as 
nitrogenous  guanos.  They  are  the  excreta  of  sea  fowls.  Be- 
fore the  phosphate  deposits  were  discovered  in  the  United  States 
these  guanos  were  imported  into  this  country  and  used  largely  by 
the  manufacturers.  All  of  these  guanos  originally  contained 
nitrogen.  However  the  nitrogen,  soluble  phosphates,  and 
alkalies  have  disappeared  by  decomposition  of  organic  matter 
and  leaching  of  water,  so  that  most  of  them  only  contain  traces  of 
nitrogen.  The  phosphoric  acid  is  in  the  form  of  tricalcium  phos- 
phate and  insoluble  in  water.  Some  of  these  guanos  contain  too 
much  iron  and  alumina  oxides  to  manufacture  profitably.  They 
are  not  imported  into  the  United  States  very  much  now,  as  many 
of  the  deposits  are  exhausted  or  else  too  expensive  to  compete 
with   our  native  mineral  phosphates.* 

It  should  be  understood  that  there  are  many  other  phosphates 
used  in  other  countries  but  they  cannot  compete  with  our  mineral 
phosphates  and  therefore  are  not  found  on  the  American  market. 

>  Wiley,  Principles  and  Practice  of  Agricultural  Analysis,  Vol.  II. 


I'HOSPHATliS 


71 


Classification  of  Phosphates. — From  the  foregoing  it  is  shown 
that  there  are  three  classes  of  phosphates  used  for  fertiHzing 
purposes. 

(      Raw  bone-meal 


Bone  phosphates 


Steamed  bone-meal 
Bone-black 
Bone-ash 
Bone  tankage 
Dry  ground  fish 

Florida  \ 


South  Carolina 


Rock  phosphates      { 


Tennessee 


Land  pebble 
River  pebble 
Hard  rock 

Land  rock 
River  rock 

Brown  rock 
Blue  rock 
White  rock 


Apatite 

Rodunda  phosphate 
[      Phosphatic  guanos. 

3.  Basic  slag  phosphates. 

(3f  the  bone  phosphates,  bone-ash  is  not  found  much  on  the 


Fig.  8.— The  hog;  one  of  the  sources  of  bone  phosphate. — Courtesy  of  the 
Wisconsin  Exp.  Station. 

American  market  and  bone-black  is  usually  acidulated   (treated 


78  FERTILITY  AND  FERTILIZER   HINTS 

with  sulphuric  acid)  before  being  applied  as  fertilizer.  The 
production  of  rock  phosphates  in  the  United  States  has  almost 
entirely  discouraged  the  importation  of  the  mineralized  or  phos- 
phatic  guanos. 

Form  of  the  Phosphates. — The  phosphoric  acid  in  bone  phos- 
phates and  rock  phosphates  is  in  the  form  of  tricalcium  phos- 
phate. Bone  phosphates  are  always  as  phosphate  of  lime  while 
rock  phosphates  contain  more  or  less  impurities  as  iron,  alumina 
and  silica.  It  is  customary  to  apply  the  name,  "bone  phosphate 
of  lime,"  to  the  phosphate  present  in  rock  phosphates,  although 
tricalcium  phosphate  is  the  correct  name.  The  phosphoric  acid 
in  basic  slag  is  not  in  the  same  form  as  in  the  other  phosphates. 
It  was  formerly  accepted  that  the  phosphoric  acid  in  basic  slag 
existed  as  tetra-calcium  phosphate,  but  HalF  claims  that  the 
phosphoric  acid  is  in  the  form  of  double  phosphate  and  silicate 
of  calcium  Ca,,(CaO)   (PO,).,CaSiO,. 

Availability  of  the  Phosphates. — All  of  the  phosphates  are 
slowly  available  as  plant  food  and  practically  insoluble  in  water. 
The  phosphoric  acid  in  phosphates  is  not  entirely  used  the  first 
year  so  that  maximum  crop  returns  cannot  be  expected  im- 
mediately, but  the  continued  use  of  phosphates  give  good  results. 
For  quick  growing  crops  the  phosphates  are  not  always  desirable. 
The  phosphates  from  bones  are  perhaps  more  readily  decomposed 
than  the  rock  phosphates.  There  is  more  or  less  organic  matter 
in  bones  which  decays  quite  rapidly  and  attacks  tHe  phosphoric 
acid  with  which  it  is  closely  associated.  In  the  rock  phosphates 
there  is  no  organic  decay  and  the  impurities  as  iron  and  alumina 
retard  to  a  certain  extent  the  fermentation  and  decomposition 
of  the  phosphoric  acid  present.  Basic  slag  phosphate  as  shown 
by  the  statistics  in  this  chapter,  is  used  extensively  in  Europe. 
European  experiments  show  that  this  material  is  of  higher  avail- 
ability than  the  insoluble  bone  and  rock  phosphates. 

The  nature  of  the  soil  has  a  great  deal  to  do  with  the  avail- 
ability of  phosphates.  Soils  in  good  tilth  will  disintegrate  the 
phosphates  more  readily  than  those  in  poor  physical  condition. 
The  sandy  and  gravel  soils  are  liable  to  give  poorer  results  than 

'  Fertilizers  and  Manures. 


PHOSPHATES  79 

clay  soils  or  soils  containing  considerable  organic  matter  and 
potash.  Organic  matter  tends  to  promote  fermentations  which 
attack  the  phosphates  and  make  them  available  as  plant  food, 
and  with  the  aid  of  potash,  it  tends  to  act  upon  the  lime  of  the 
phosphates.  The  kind  of  crop  also  influences  the  rate  of  de- 
composition of  phosphates.  Some  plants  are  more  able  to  make 
use  of  the  phosphoric  acid  of  phosphates  than  others.* 


CHAPTER  VIII. 


SUPERPHOSPHATES  AND  EFFECT  OF  PHOSPHORIC  ACID. 

The  phosphates  mentioned  in  the  previous  chapter,  with  the 
exception  of  basic  slag,  are  not  always  used  in  the  raw  condi- 
tion for  fertilizing  purposes,  but  are  treated  with  sulphuric  acid 
in  the  manufacture  of  commercial  or  artificial  fertilizers  to  make 
the  phosphoric  acid  available;  that  is,  to  convert  the  phosphoric 
acid  into  forms  that  may  readily  be  used  by  the  plant  as  food. 

Manufacture  of  Super  or  Acid  Phosphate. — The  manufacturing 
of  artificial  fertilizers  began  some  time  after  1840  in  which  year 
Liebig,  a  German  scientist,  discovered  that  by  adding  sulphuric 
acid  (oil  of  vitriol)  to  bones  the  phosphoric  acid  was  made 
soluble.  This  discovery  paved  the  way  for  the  manufacture  of 
commercial  fertilizers  which  are  sold  in  such  large  quantities 
to-day. 

Manufacturing  Sulphuric  Acid. — The  manufacture  of  super- 
phosphate is  rather  tecTmical  but  a  knowledge  of  this  important 
industry  may  prove  of  interest.  To  begin  with,  the  manufac- 
turer purchases  pyrites  or  brimstone  and  phosphate  rock.  Py- 
rites is  a  compound  of  sulphur  and  iron  and  is  obtained  from 
Spain  and  mines  in  this  country.  The  pyrites  or  brimstone 
are  burned  in  special  burners  and  the  sulphurous  gases  are  mixed 
with  nitrous  gases  obtained  from  nitrate  of  soda.  These  mixed 
sulphurous  and  nitrous  gases  are  introduced  into  large  high  lead 
towers  and  then  into  lead  chambers  which  are  also  large  and 
high.  Steam  is  introduced  into  the  lead  chambers,  mixed  with 
the  gases  and  sulphuric  acid  is  formed  which  falls  to  the  bot- 
tom as  a  liquid.  These  lead  towers  and  lead  chambers  are  very 
costly. 

Making  Superphosphate. — The  manufacturer  purchases  phos- 
phates that  contain  sufficient  tricalcuim  phosphate  to  warrant 
profitable  treatment.  Phosphates  that  contain  considerable  im- 
purities as  iron  and  alumina  are  avoided.  The  phosphate  rock 
is  broken  into  small  pieces  and  then  pulverized.  Certain  amounts, 
say  1,000  pounds,  of  phosphate  powder  and  dilute  sulphuric  acid 


SUPERPHOSPIiATF.S  AND  EFFECT  OF  PHOSPHORIC  ACID  8l 

are  thoroughly  mixed  together  by  special  machinery  and  con- 
veyed to  a  pit  where  the  mixture  is  allowed  to  remain  until 
ready  for  shipment.  . 

Chemistry  of  the  Process. — The  phosphoric  acid  is  in  the  form 
of  tricalcium  phosphate  in  phosphates,  or  three  parts  of  lime  are 
united  with  one  part  of  phosphoric  acid.  When  the  sulphuric 
acid  is  added  it  attacks  the  phosphate  and  dissolves  it,  setting 
free  two  parts  of  lime  (that  were  originally  combined  with  the 
phosphoric  acid)  which  unite  or  combine  with  the  sulphuric  acid 
forming  superphosphate  (one  lime  phosphate  or  mono-calcic 
phosphate)  and  gypsum  (sulphate  of  lime).  In  other  words  the 
phosphoric  acid  in  superphosphate  is  only  combined  with  one 
part  of  lime  as  the  remaining  two  parts  of  lime,  with  which  the 
phosphoric  acid  was  formerly  combined,  have  been  set  free.  From 
the  above  it  is  evident  that  superphosphate  is  made  up  of  one 
lime  (mono-calcic)  phosphate  and  gypsum  (sulphate  of  lime). 
Or  the  reaction  is : 

(sCaO  P2O5)     +    2(H,OS03)     =:      {Ca02H20P.,05)     +    alCaOSOj) 
Tricalcic  phosphate  Sulphuric  acid  Monocalcic  phosphate    Gypsum 

Phosphates  of  Lime. — In  the  phosphoric  acid  fertilizers  used 
there  are  four  different  forms  of  phosphates  of  lime,  all  of  differ- 
ent availability.  These  phosphates  of  lime  are  known  as  the  in- 
soluble, soluble,  reverted,  and  basic  slag  forms. 

1.  Insoluble  Phosphoric  Acid. — The  most  common  form  of  phos- 
phate of  lime  is  that  which  is  found  in  bones,  mineral  phosphates, 
guanos,  etc.,  and  is  called  insoluble.  The  lime  and  phosphoric 
acid  are  combined  a?  three  parts  of  lime  and  one  of  phosphoric 
acid.  This  is  called  tricalcic,  tribasic,  bone  phosphate  and  three 
lime  phosphate.     We  may  represent  this  form  as  follows: 

Lime    C 

Lime    <     Phosphoric  acid. 

Lime    ( 

This  is  the  most  insoluble  form  of  phosphate  of  lime  and  is 
called  insoluble  phosphoric  acid. 

2.  Soluble  Phosphoric  Acid. — When  insoluble  phosphate  of  lime 
is  acted  upon  by  sulphuric  acid,  two  parts  of  lime  are  replaced 
by  two  parts  of  water  and  soluble  phosphate  of  lime  is  formed. 


82  1-ERTlLITV    AND   FERTILIZER    HINTS 

This  soluble  phosphate  is  called  super  or  acid  phosphate  and  is 
a  saturated  compound.  It  is  also  known  as  monobasic,  mono- 
calcic,  and  one  lime  phosphate. 

This  compound  may  be  graphically  represented  as : 

Lime      ( 

Water    -     Phosphoric  acid. 

Water    ( 

This  form  is  entirely  soluble  in  water  and  readily  available  as 
plant  food.  It  is  the  highest  valued  form  of  phosphate  of  lime 
and  is  called  soluble  phosphoric  acid. 

3.  Reverted  Phosphoric  Acid. — Between  the  soluble  and  in- 
soluble phosphate  of  lime  there  is  another  form  known  as  re- 
verted, citrate  soluble,  dicalcic,  and  two  lime  phosphate,  in  which 
there  are  two  parts  of  lime  and  one  part  of  water  as  represented : 

Lime      ( 

Lime      -     Phosphoric  acid. 

Water    ( 

The  name  reverted  is  applied  to  this  form  of  phosphate  of 
lime  because  it  is  formed  by  reversion  or  retrograding  of  some 
of  the  soluble  towards  the  insoluble.  This  form  is  not  as  soluble 
as  the  soluble  phosphoric  acid  and  is  more  soluble  than  the  in- 
soluble form.  It  is  insoluble  in  water,  but  the  weak  acids  of  the 
soil  render  it  favorable  for  plant  food.  The  sum  of  the  soluble 
and  the  reverted  is  called  available,  because  both  forms  may  be 
used  by  plants. 

4.  Basic  Slag  Phosphate. — It  used  to  be  accepted  that  the  three 
forms  just  described  were  the  only  forms  of  phosphoric  acid. 
However,  the  phosphate  of  lime  in  basic  slag  is  in  another  form. 
It  was  supposed  that  one  part  of  phosphoric  acid  was  combined 
v^^ith  four  parts  of  lime,  and  in  this  form  it  was  known  as  tetra- 
calcic,  tetrabasic,  and  four  lime  phosphate. 

Lime    ( 

]^^l   \     Phosphoric  acid 
Lime    ( 
Recently,  however,  there  seems  to  be  some  uncertainty  as  to 
whether  or  not  the  phosphoric  acid  in  basic  slag  exists  as  tetra- 


SUPERPHOSPHATES  AND  EEEECT  OE   PHOSPHORIC   ACID  83 

calcic  phosphate  of  lime.  HalF  says  it  exists  as  double  silicate 
and  phosphate  of  lime  (CaO).,  PoOBSiO^.  Whatever  may  be 
the  form  of  combination  of  the  phosphoric  acid  in  basic  slag,  it 
is  easily  attacked  by  soil  water,  and  is  more  available  than  any 
of  the  forms  of  tricalcium  phosphate,  though  usually  less  than 
superphosphate/^ 

Value  of  Reverted  Phosphoric  Acid. — The  value  of  reverted 
phosphate  is  a  subject  which  has  given  rise  to  much  dispute  among 
chemists.  That  it  has  a  higher  value  than  the  ordinary  insoluble 
phosphate  is  now  admitted,  but  in  this  country,  (England)  in 
the  manure  trade,  this  is  not  as  yet  recognized.  At  first  it  was 
thought  that  it  was  impossible  to  estimate  its  quantity  by  chemical 
analysis.  This  difficulty,  however,  has  been  overcome,  and  it  is 
generally  admitted  that  the  ammonium  citrate  process  furnishes 
an  accurate  means  of  determining  its  amount.  Both  on  the  con- 
tinent and  in  the  United  States  reverted  phosphoric  acid  is  rec- 
ognized as  possessing  a  monetary  value  in  excess  of  that  possessed 
by  the  ordinary  insoluble  phosphates.  The  result  is.  that  raw 
mineral  phosphates  containing  iron  and  alumina  to  any  apprec- 
iable extent  are  not  used  in  this  country  (England),  although 
they  do  find  a  limited  application  in  America  and  on  the  conti- 
nent.'^ * 

Difference  Between  Phosphates  and  Superphosphates. — It  is  cus- 
tomary among  some  farmers  to  call  every  fertilizer  a  phosphate 
and  among  others  this  name  is  used  for  the  product — superphos- 
phate. A  phosphate  is  a  product  containing  phosphoric  acid  as  its 
main  ingredient,  in  the  insoluble  form,  as  bone  phosphates,  rock- 
phosphates  and  basic  slag  phosphates.  A  superphosphate  is  a  fertil- 
izer containing  principally  soluble  phosphoric  acid.  The  phosphates, 
except  basic  slag  and  Rodunda  phos])hate,  may  be  manufactured 
into  superphosphates  by  the  addition  of  sulphuric  acid  as  previous- 
ly mentioned  in  this  chapter.  Thus  we  have  superphosphates  from 
bones  and  minerals,  as  raw  bone  superphosphate,  steamed  bone 
superphosphate,  bone-ash  superphosphate,  bone-black  superphos- 
phate, Florida  hard  rock  superphosphate,  Florida  pebble  superphos- 

'  Fertilizers  and  Manures. 

s  Akiman,  Manures  and  Manuring. 


84  FERTILITY  AND  FERTILIZER   HINTS 

phate,  Florida  soft  rock  superphosphate,  South  Carolina  land  rock 
superphosphate,  South  Carolina  river  rock  superphosphate,  Ten- 
nessee brown  rock  superphosphate,  Tennessee  blue  rock  super- 
phosphate, Tennessee  white  rock  superphosphate,  etc.  Of  course 
all  of  these  superphosphates  will  not  contain  the  same  amounts 
of  soluble  phosphoric  acid,  as  the  mode  of  manufacture  and  con- 
tent of  phosphoric  acid  in  the  raw  products  determine  this.  A 
superphosphate  made  from  bone-black  containing  30  per  cent,  of 
phosphoric  acid  will  be  richer  in  soluble  phosphoric  acid  than 
one  made  from  South  Carolina  land  rock  running  23  per  cent,  of 
phosphoric  acid.  Bone-black  and  bone-ash  because  of  their 
higher  phosphoric  acid  contents  make  richer  superphosphates  than 
those  manufactured  from  most  of  the  mineral  phosphates. 

Some  Names  Applied  to  Superphosphates. — Acid  phosphate,  dis- 
solved bone,  dissolved  bone-black  and  dissolved  bone-ash  are 
names  that  are  used  indiscriminately  by  the  trade.  A  manufac- 
turer may  call  a  product  made  from  rock  phosphate,  "dissolved 
bone,"  and  sell  it  under  this  name.  Dissolved  bone,  strictly 
speaking,  is  dissolved  bone  superphosphate,  or  a  superphosphate 
made  from  raw  or  steamed  bones.  Dissolved  bone-black  is  a 
superphosphate  manufactured  from  bone-black.  Dissolved  bone- 
ash  is  a  superphosphate  made  from;  bone-ash.  The  superphos- 
phates made  from  rock  phosphates  are  usually  called  acid  phos- 
phates by  the  trade,  although  this  latter  term  is  applied  to  any 
superphosphate  and  is  perhaps  a  more  common  name  in  the  United 
States  than  superphosphate.  For  superphosphates  made  from 
ground  rock  phosphate,  acid  phosphate  is  perhaps  a  more  correct 
name  as  it  is  the  phosphate  acted  upon  by  acid. 

Available  Phosphoric  Acid. — There  seems  to  be  a  great  deal  of 
confusion  among  farmers  over  what  constitutes  available  phos- 
phoric acid  and  this  is  not  to  be  wondered  at  when  one  con- 
siders the  number  of  terms  applied  to  reverted  and  insoluble 
phosphoric  acid.  Reverted  phosphoric  acid  is  soluble  in  the  weak 
acids  of  the  soil.  The  chemist  uses  a  solution  called  ammonium 
citrate  or  citrate,  which  has  a  similar  action  to  the  weak  soil 
acids,  in  dissolving  out  this  form  of  phosphoric  acid.  For  this 
reason  the  term  citrate  soluble  is  often  applied  to  reverted  phos- 


SUPERPHOSPHATES  AND   EFFECT  OF   PHOSPHORIC   ACID  85 

phoric  acid.     The  insoluble  phosphoric  acid  is  not  soluble  in  this 
citrate  solution  but  it  is  soluble  in  strong  acids,  hence  the  names 
citrate  insoluble  and  acid  soluble  are  applied  to  insoluble  phos- 
phoric acid. 
Reverted  phosphoric  acid  is  equivalent  to  citrate  soluble  phosphoric  acid. 

T»,o^i„Ki^  r.v,^o.,T,^^;^  ^^iA  ;.^^„j   oi^„f  f^  '  citrate  insoluble  phosphoric  acid 
Insoluble  phosphoric  acid  IS  equivalent  to  s       •,      ,   ,,       1      *^i.     ■  j 

^       ^  ^  (  acid  soluble  phosphoric  acid. 

The  sum  of  the  soluble  and  reverted  phosphoric  acid  is  called 
available  phosphoric  acid,  or  the  sum  of  the  soluble  and  citrate 
soluble  phosphoric  acid  is  available  phosphoric  acid.  The  farmer 
often  confuses  the  term  acid  soluble  as  belonging  to  the  available 
phosphoric  acid  on  account  of  the  use  of  the  word  soluble. 
Again,  the  difference  between  the  total  phosphoric  acid  (which  is 
the  sum  of  the  soluble,  reverted  and  insoluble  forms)  and  the 
insoluble  phosphoric  acid  is  available  phosphoric  acid.* 

The  Difference  of  the  Forms  of  Phosphoric  Acid  in  Superphos- 
phates.— In  the  manufacture  of  superphosphates  not  all  of  the 
tricalcium  phosphate  is  converted  into  soluble  phosphoric  acid. 
The  manufacturer  generally  calculates  to  add  just  enough  acid 
to  convert  most  of  the  phosphoric  acid  into  the  soluble  form. 
However,  he  does  not  wish  to  add  too  much  acid  in  order  to  put 
out  a  profitable  marketable  product.  Hence  most  of  the  superphos- 
phates found  on  the  market  contain  some  insoluble  phosphoric 
acid,  ranging  perhaps  from  a  few  hundredths  to  as  high  as  four 
per  cent,  in  poor  acidulation.  This  insoluble  phosphoric  acid 
in  superphosphates  is  different.  That  in  the  lx)ne  superphos- 
phates is  of  more  value  as  regards  availability  than  the  in- 
soluble phosphoric  acid  in  the  mineral  superphosphates.  The  in- 
soluble phosphoric  acid  is  also  of  different  value  in  the  mineral 
superphosphates  depending  upon  the  nature  or  purity  of  the  rock 
from  which  they  were  made.  However,  the  insoluble  phosphoric 
acid  in  super  or  acid  phosphates  is  generally  present  in  small 
amounts  and  would  only  have  to  be  seriously  considered  when  the 
acidulation  proves  insufficient.  The  soluble  phosphoric  acid  in  all 
superphosphates  is  the  same,  whether  the  superphosphates  are 
made  from  lx)nes,  bone-ash,  bone-black,  or  any  of  the  mineral 
phosphates.     It  is  an  erroneous  opinion  among  some,  that  the 


86  FERTILITY   AND  FERTILIZER   HINTS 

material  from  which  the  superphosphate  is  made  influences  the 
value  of  the  soluble  phosphoric  acid.  Many  farmers  would  rather 
purchase  soluble  phosphoric  acid  as  superphosphates  manufac- 
tured from  bones  than  soluble  phosphoric  acid  from  mineral  sup- 
erphosphates. There  is  not  any  difference  in  the  soluble  phos- 
phoric acid  of  superphosphates  no  matter  what  raw  material  is 
used  in  making  it.  Of  course  a  dissolved  bone  superphosphate 
will  perchance  give  better  results  than  a  raw  rock  superphos- 
phate of  equal  soluble  phosphoric  acid  composition  as  the  dis- 
solved bone  superphosphate  will  contain  in  addition  to  the  phos- 
phoric acid,  a  certain  amount  of  nitrogen,  so  if  we  judge  the 
value  of  soluble  phosphoric  acid  in  this  way  we  are  assuming 
an  unequal  and  unfair  task. 

Some  Farmers  Favor  Bone  Superphosphates. — Many  farmers 
seem  to  be  predjudiced  against  the  mineral  superphosphates  and 
always  demand  superphosphates  made  from  bone.  Often  the 
price  is  much  higher  for  the  bone  superphosphates  on  account 
of  the  greater  price  bones  bring  when  sold  for  bone-black,  manu- 
facturing interests,  etc.  These  farmers  could  generally  purchase 
their  phosphoric  acid  more  cheaply  from  mineral  superphosphates. 
Of  course  when  dissolved  bone  and  mineral  superphosphate  of 
equal  available  phosphoric  acid  content,  are  offered  for  the  same 
price,  it  is  more  economical  to  select  the  dissolved  bone ;  but  it 
is  seldom  that  one  can  get  such  a  bargain  as  the  dealers  in  fer- 
tilizers always  charge  for  the  ammonia  content.  Generally  phos- 
phoric acid  can  be  purchased  cheaper  from  mineral  superphos- 
phates than  from  dissolved  bone  superphosphates. 

Double  Superphosphate. — This  is  sometimes  called  double  phos- 
phate. This  double  superphosphate  is  manufactured  as  follows: 
Phosphates  are  treated  with  an  excess  of  sulphuric  acid  (chamber- 
acid)  and  the  phosphoric  acid  is  dissolved  out  as  free  phosphoric 
acid.  The  fluids,  sulphuric  acid  and  phosphoric  acid  are  fil- 
tered or  separated  from  the  insoluble  matter  and  concentrated. 
This  concentrated  solution  is  then  used  in  dissolving  high  grade 
phosphates  and  the  resulting  product  is  called  double  superphos- 
phate because  the  phosphoric  acid  content  is  more  than  double 


SUPERPHOSPHATES  AND  EFFECT  OF   PHOSPHORIC   ACID  87 

and  generally  three  times  as  much  as  in  superphosphates.  Wiley^ 
suggests  that  superphosphate  is  a  more  correct  name  for  this , 
class  of  material  as  it  is  a  phosphate  acted  upon  by  free  phos- 
phoric acid  and  superior  to  acid  phosphate.  Phosphates  contain- 
ing too  low  a  percentage  of  phosphate  of  lime  for  profitable  manu- 
facture of  acid  phosphate  may  be  utilized  in  obtaining  the  free 
phosphoric  acid. 

Not  much  double  superphosphate  is  found  on  the  American 
market  but  it  is  quite  popular  in  Germany  where  it  is  manufac- 
tured principally.  Double  superphosphates  contain  about  40  to 
45  per  cent,  of  available  phosphoric  acid.  They  contain  less  im- 
purities than  acid  phosphates.  The  phosphoric  acid  is  present 
in  the  same  forms  as  in  acid  phosphate,  namely  as  soluble,  re- 
verted and  insoluble  phosphoric  acid.  Double  superphosphates 
are  expensive  but  sometimes  economical  to  purchase  when  freight 
is  high. 

No  Free  Acid  in  Treated  Phosphates. — Acid  phosphates  and 
double  superphosphates  when  well  manufactured  do  not  contain 
any  free  acid  as  all  of  the  sulphuric  acid  is  united  with  lime  and 
forms  gypsum.  Of  course  it  is  possible  for  a  manufacturer  to 
make  a  product  that  will  contain  free  acid,  but  this  is  not  done 
and  the  product  delivered  to  the  trade  does  not  contain  any  free 
acid. 

The  Color  of  an  Acid  Phosphate. — There  seems  to  be  a  prefer- 
ence among  some  for  a  light  colored  acid  phosphate  while  others 
demand  a  dark  colored  product.  The  color  and  nature  of  the 
raw  material  from  which  acid  phosphates  are  made  determine 
their  final  color.  The  manufacturers  in  order  to  satisfy  the  trade 
often  carry  two  different  colored  acid  phosphates  of  the  same 
chemical  composition  which  are  made  from  the  same  raw  product. 
The  dark  or  black  color  is  obtained  by  mixing  in  lamp-black 
when  the  final  product  is  not  sufficiently  dark.  Some  raw  ma- 
terials as  bone,  bone-black,  etc.,  produce  a  black  superphosphate 
without  the  addition  of  any  coloring  substance.  The  color  of 
an  acid  phosphate  does  not  indicate  its  fertilizing  value.* 

'  Principles  and  Practice  of  Agricultural  Analysis,  Vol.  II. 
7 


88  FERTILITY   AND  FERTILIZER   HINTS 

How  to  Make  Superphosphate  at  Home. — Sometimes  farmers 
live  far  away  from  places  where  fertilizers  may  be  purchased 
and  should  such  farmers  save  the  bones  that  accumulate  on  the 
farm,  superphosphate  may  be  made  at  home.  The  process  may 
be  conducted  as  follows :  Break  up  the  bones  in  as  small  pieces 
as  possible  and  add  one-third  their  weight  of  water  to  them  in  a 
long  wooden  trough  lined  with  sheet  lead  or  with  a  thick  coat- 
ing of  pitch ;  the  lead  is  better.  To  the  bones  and  water,  add 
very  slowly  sulphuric  acid  (oil  of  vitriol).  This  acid  must  be 
added  very  slowly  as  great  heat  is  evolved  on  the  addition  of  sul- 
phuric acid  to  water.  The  amount  of  acid  to  add  depends  upon 
its  strength  or  concentration.  About  one-third  the  weight  of 
the  bones  of  strong  white  sulphuric  acid  or  one-half  of  the  brown 
sulphuric  acid  should  suffice.  The  whole  mass  should  be  thor- 
oughly mixed  with  a  wooden  shovel,  allowed  to  stand  for  an  hour 
and  removed  to  some  dry  place  and  stored  for  two  months  when 
it  will  be  ready  for  the  land.  If  sulphuric  acid  gets  on  your 
clothes  it  will  ruin  them  and  it  will  burn  the  skin  wherever  it 
touches  it.* 

Amount  of  Phosphoric  Acid  in  Soils. — The  phosphoric  acid  in 
soils  is  generally  found  in  largest  amounts  in  the  surface  soil  and 
is  usually  derived  from  the  disintegration  of  rocks.  It  is  often 
deficient  and  many  soils  show  only  traces  of  phosphoric  acid. 
Even  fertile  soils  only  contain  small  amounts  of  this  constituent. 
Soils  average  from  traces  to  0.25  per  cent,  of  phosphoric  acid. 
We  may  figure  than  an  average  soil  contains  about  3,500  to  4,000 
pounds  phosphoric  acid  per  acre.  Only  a  small  amount  of  this 
is  available.  Some  soils  may  contain  larger  quantities  of  phos- 
phoric acid  but  the  poor  condition  of  the  soil  keeps  this  locked  up 
so  that  plants  cannot  utilize  it.  Organic  matter,  lime  and  good 
tillage  help  to  increase  the  available  supply  of  phosphoric  acid. 

Fixation  of  Phosphoric  Acid. — When  soluble  phosphoric  acid 
is  added  to  soil  it  becomes  fixed  and  does  not  wash  out  readily. 
It  is  generally  supposed  that  soluble  phosphoric  acid  from  fer- 
tilizers becomes  readily  distributed  and  unites  with  the  minerals 
forming  compounds  insoluble  in  water ;  the  phosphoric  acid  in 
«;oluble  phosphoric  acid  is  in  a  very  finely  divided  state  and  the 


SUPERPHOSPHATES  AND   El'I^ECT  OE   PHOSPHORIC   ACID  89 

distribution  takes  place  before  the  insoluble  compounds  are 
formed.  Soils  rich  in  lime  readily  fix  phosphoric  acid  and  a 
certain  amount  is  probably  fixed  in  combination  with  iron  and 
alumina.  Experiments  show  that  phosphoric  acid  is  not  carried 
away  by  leaching  to  any  extent.  All  soils  are  not  of  equal  fixa- 
tion value ;  most  soils  fix  phosphoric  acid  but  some  are  better 
equipped  to  perform  this  process  than  others.  Clay  soils  rich  in 
lime  fix  phosphoric  acid  very  rapidly  while  soils  deficient  in  lime 
act  much  slower  in  this  respect.  Sandy  and  gravel  soils,  lacking 
in  organic  matter  and  clay,  do  not  fix  the  phosphoric  acid  rapidly.* 

Functions  of  Phosphoric  Acid. — Phosphoric  acid  hastens  maturi- 
ty of  crops.  It  has  a  ripening  effect  and  seems  to  hasten  grain 
and  fruit  formation ;  it  increases  the  yield  of  grain  ;  it  stimulates 
root  development  in  young  plants. 

Phosphoric  acid  helps  in  transferring  substances  from  the 
stalks,  leaves,  and  other  growing  parts  to  the  seed.  Certain  sub- 
stances are  aided  by  phosphoric  acid  by  being  rendered  soluble 
enough  to  pass  through  the  plant  tissues. 

Phosphoric  acid  helps  to  build  up  protein  substances  in  the 
plant  as  certain  proteid  bodies  require  phosphoric  acid  for  their 
complete  development.  Therefore  a  lack  of  phosphoric  acid 
would  necessarily  cause  the  plant  to  suffer.* 

The  kind  af  phosphate  to  use  depends  upon  the  crop  and  the 
soil.  As  a  general  rule  the  best  immediate  results  are  secured 
from  those  phosphates  that  are  acidulated  and  the  raw  phosphates 
are  slower  acting  and  not  so  suitable  for  weak  feeding  crops. 
To  get  the  full  benefit  from  raw  products  sometimes  requires 
two  or  three  seasons,  so  that  a  farmer  employing  slowly  avail- 
able products  should  plan  to  add  enough  each  year  to  supply 
the  crop  with  sufficient  available  phosphoric  acid.* 


CHAPTER  IX. 


POTASH  FERTILIZERS. 

Before  the  discovery  of  the  potash  mines  in  Stassfurt,  Ger- 
many, the  main  source  of  supply  of  potash  was  wood  ashes. 

History. — The  following  description  tells  how  the  deposits 
of  potash  salts  were  formed. 

The  Stassfurt  salt  and  potash  deposits  had  their  origin,  thous- 
ands of  years  ago,  in  a  sea  or  ocean,  the  waters  of  which  gradual- 
ly receded,  leaving  near  the  coast,  lakes  which  still  retained  com- 
munication with  the  great  ocean  by  means  of  small  channels.  In 
that  part  of  Europe  the  climate  was  then  tropical,  and  the  waters 
of  these  lakes  rapidly  evaporated,  but  were  constantly  replenished 
through  these  small  channels  connecting  them  with  the  main 
body.  Decade  after  decade  this  continued,  until  by  evaporation 
and  crystallization  the  various  salts  present  in  the  sea  water  were 
deposited  in  solid  form.  Overlying  the  deposits  is  a  layer  of 
impervious  clay  which  acts  as  a  water-tight  roof  to  protect  and 
preserve  the  very  soluble  salts.* 

Potash  Salts  Used  for  Fertilizing  Purposes. — The  principal  pot- 
ash salts  obtained  from  these  mines  that  are  used  as  fertilizers  in 
the  United  States  are : 

1.  Kainit 

2.  Sylvinit 

3.  Muriate  of  potash 

4.  Sulphate  of  potash 

5.  Double  sulphate  of  potash  and  magnesia 

6.  Potassium — magnesium  carbonate. 

These  products  may  be  classified  as  crude  and  manufactured  as 
follows : 

Crude  salts  |    Kainit 

Natural  products        (    Sylvinit 

(  Muriate  of  potash 

Manufactured  salts    !  Sulphate  of  potash 

Concentrated  salts     j  Double  sulphate  of  potash  and  magnesia 

1^  Potassium-magnesium  carbonate. 

There   are   many    other   salts    as    carnallit,    polyhalit,    krugit, 


POTASH    I'KRTILIZERS  9 1 

hartsalz,  sylvin,  kieserit  and  schonit  found  in  these  deposits  but 
are  not  usually  sold  on  the  American  market. 

1.  Kainit  as  sold  in  this  country  is  a  finely  ground,  gray 
colored  and  contains  small  red  and  yellow  particles.  This  pot- 
ash salt  has  been  used  more  extensively  in  this  country  than  any 
of  the  others,  but  the  kainit  deposits  are  gradually  becoming  ex- 
hausted so  that  it  is  not  so  common  on  our  markets  as  formerly. 
Kainit  is  made  up  of  potassium,  sodium  and  magnesium  chlorides, 
and  potassium,  magnesium  and  calcium  sulphates.  The  potash 
is  present  chiefly  as  sulphate  but  on  account  of  the  large  amounts 
o_f  sodium  and  magnesium  chlorides  present,  the  potash  has  the 
same  action  as  if  it  were  chloride.  Kainit  usually  contains  12  to 
12.5  per  cent,  of  potash.* 

2.  Sylvinit. — This  salt  when  ground  is  much  more  red  in  color 
than  kainit.  It  is  being  used  more  in  this  country  than  formerly 
because  of  the  scarcity  of  true  kainit.  It  is  often  sold  in  the 
United  States  by  the  fertilizer  manufacturers  under  the  name  of 
kainit.  Sylvinit  consists  chiefly  of  chlorides ;  in  fact  is  is  com- 
posed principally  of  sodium  chloride  and  potassium  chloride.  It 
carries  from  12.5  to  15.5  per  cent,  of  potash.* 

3.  Muriate  of  Potash. — As  has  been  said,  this  product  is  a 
manufactured  one.  It  is  sold  in  large  quantities  in  this  country. 
The  crude  salts  of  the  mines  are  refined,  during  which  process 
most  of  the  useless  impurities  are  removed,  as  lime,  magnesia, 
soda,  etc.  The  principal  grades  of  muriate  of  potash  as  manu- 
factured are: 

Actual  potash  (KjO) 
Per  cent. 

=  46.7 

=  52.7 

=  57.9 

=  62.0 

The  product  sold  in  the  United  States  usually  contains  80  per 
cent,  of  muriate  of  potash  which  is  equivalent  to  50.5  per  cent, 
of  potash.* 

4.  Sulphate  of  Potash. — This  is  a  yellow,  dry,  almost  powdery 
substance.     It  is  sold  containing  90  to  97  per  cent,  of  sulphate  of 


riat 

eo 

PC 

potash  (KC 
r  cent. 

70  to 
80  to 

75 
85 

90 

to 

95 

98 

92  FERTILITY  AND  FERTILIZER   HINTS 

potash  which  is  equivalent  to  46  to  52  per  cent,  of  potash.  High 
grade  sulphate  of  potash  containing  50  per  cent,  of  potash  is  most- 
ly used  in  America. 

Sulphate  of  potash   is   more   expensive  than   muriate   because 


Fig.  9.  -Tobacco;  a  crop  that  is  injured  by  excessive  chlorides. — After 
Conn.  Exp.  Station. 

the  cost  of  manufacture  is  more,  but  it  is  desirable  for  tobacco, 
potatoes,  citrous  fruits,  and  other  crops  that  are  injured  by  ex- 
cessive chlorides.* 

5.  Double  Sulphate  of  Potash  and  Magnesia. — This  product  is 
somewhat  similar  in  action  on  crops  to  high  grade  sulphate  of 
potash.  It  contains  considerable  sulphate  of  magnesia  which  is 
believed  to  exert  a  beneficial  effect.  It  usually  carries  about  26 
per  cent,  of  potash.  It  is  not  used  to  any  great  extent  in  this 
country,  except  by  some  fruit  growers  who  prefer  it  to  sulphate 
of  potash.* 

Potash  Manure  Salts. — There  are  other  potash  salts  that  vary 
from  20  to  30  per  cent,  of  potash  called  double  manure  salts  and 


POTASH    FERTILIZERS  93 

potash  manure  salts  which  are  not  used  extensively  in  fertilizers ; 
although  a  potash  manure  salt  containing  20  per  cent,  of  potash 
is  sometimes  sold  which  acts  like  kainit.* 

6.  Potassium-magnesium  Carbonate. — This  is  a  dry,  white  manu- 
factured product.  It  is  not  sold  as  extensively  as  kainit,  sylvinit, 
muriate  of  potash  and  sulphate  of  potash,  but  it  is  well  liked  by 
tobacco  growers.  It  is  also  used  in  Florida  on  oranges  and  pine- 
apples. This  product  is  an  excellent  source  of  potash  for  any 
crops  that  chlorides  prove  injurious  to.  It  usually  contains  from 
20  to  25  per  cent,  of  potash  in  the  form  of  carbonate.  On  ac- 
count of  its  dry  nature,  and  because  it  does  not  absorb  water  from 
the  atmosphere,  it  is  always  easy  to  distribute.* 

Potash  from  Organic  Sources. — Most  of  the  potash  used  in 
fertilizers  is  derived  from  the  mineral  sources  but  a  small  amount 
is  sometimes  purchased  in  the  form  of  wood  ashes,  tobacco  stems, 
cotton-seed  hull  ashes,  and  beet  molasses. 

I.  Wood  Ashes. — Before  the  discovery  of  the  Stassfurt  de- 
posits wood  ashes  were  used  more  extensively  than  now  and  were 
practically  the  chief  source  of  potash  to  be  found  on  the  American 
market.  The  potash  in  wood  ashes  is  in  a  form  (as  carbonate) 
which  is  very  desirable  for  all  plants.  The  product  offered  to  the 
trade  is  not  uniform  as  different  woods,  parts  of  the  same  wood 
as  bark,  twigs,  etc.,  and  methods  of  handling,  all  influence  the 
composition.  The  ashes  from  soft  woods  usually  contain  a  lower 
percentage  of  potash  than  the  ashes  from  hard  woods.  Leached 
wood  ashes  naturally  carry  much  less  potash  than  unleached 
ashes.  Ashes  contain  about  1.9  per  cent,  of  phosphoric  acid,  5.5 
per  cent,  of  potash  and  34  per  cent,  of  lime.  They  usually  con- 
tain more  or  less  dirt  and  moisture  which  lower  the  composition. 
The  main  source  of  wood  ashes  is  Canada  as  not  much  wood  is 
burned  in  the  United  States.* 

Value  of  Wood  Ashes. — From  a  chemical  standpoint  the  value 
of  wood  ashes  is  represented  in  the  contents  of  potash,  phosphoric 
acid  and  lime.  Ashes  have  another  value  in  improving  the  con- 
dition of  the  soil.  They  seem  to  help  to  conserve  moisture,  im- 
prove the  texture  of  soil  and  correct  acidity,  thereby  increasing 


94  FERTILITY   AND  FERTILIZER    HINTS 

the  action  of  the  organisms  that  promote  nitrification.  Most 
soils  are  benefited  by  an  appHcation  of  wood  ashes.  Grasses  and 
legumes  especially  do  well  when  wood  ashes  are  applied  as  a  top 
dressing. 

2.  Tobacco  Stems. — Wherever  cigars,  cigarettes,  smoking  and 
chewing  tobacco  are  manufactured  there  are  considerable  wastes 
of  stems  and  stalks  collected.  This  material  was  formerly  thrown 
away  or  burned.  The  burning  of  tobacco  wastes  caused  the 
nitrogen  to  be  lost.  To-day  these  wastes  are  saved  and  used  as 
fertilizer.*  Tobacco  stems  contain  2.5  per  cent,  of  nitrogen,  0.6 
per  cent,  of  phosphoric  acid  and  8  per  cent,  of  potash.  Tobacco 
stalks  carry  3.5  per  cent,  of  nitrogen,  0.4  per  cent,  of  phosphoric 
acid  and  4  per  cent,  of  potash. 

3.  Cotton-seed  Hull  Ashes. — A  few  years  ago,  before  the  value 
of  cotton-seed  hulls  as  a  feed  for  live-stock  was  known,  it  was 
the  custom  to  burn  these  hulls  in  the  furnaces  of  the  gins  of  the 
Cotton  Belt,  and  dispose  of  the  ashes  for  fertilizing  purposes. 
In  those  days  considerable  cotton-seed  hull  ashes  was  to  be  found 
on  our  markets,  but  to-day  it  is  rarely  used.  This  product  contains 
on  the  average,  24  per  cent,  of  potash  and  8.7  per  cent,  of  phos- 
phoric acid.* 

4.  Carbonate  of  Potash. — This  fertilizer  is  used  to  some  ex- 
tent by  the  tobacco  growers  of  the  Connecticut  Valley. 

It  usually  carries  63  to  65  per  cent,  of  potash  and  is  very 
alkaline.  It  is  a  white  substance  and  soluble  in  water.  It  takes 
on  moisture  readily  and  for  this  reason  it  is  usually  put  up  in 
casks.* 

5.  Beet  Molasses. — The  molasses  obtained  from  the  manufac- 
ture of  sugar  from  the  sugar-beet  is  quite  rich  in  potash  which 
gives  this  product  its  bitter  taste  thus  making  it  unpalatable  for 
human  consumption.  Beet  molasses  contains  from  10  to  15  per 
cent,  of  ash  of  which  7.5  to  12.25  P"^  cent,  is  in  the  form  of 
potash  salts. 

Amount  of  Potash  in  Soils.— Soils  generally  contain  from  o.i 
tc  0.5  per  cent,  of  jwtash,  which  is  equivalent  to  3,500  to  18,000 
pounds  of  potash  per  acre  to  a  depth  of  one  foot.     Most  of  this 


POTASH    FERTIIvIZERS  95 

potash  is  not  available  to  plants  and  so  a  soil  apparently  rich  in 
potash  will  often  be  helped  by  a  supply  in  artificial  forms.  The 
addition  of  lime  often  increases  the  supply  of  available  potash 
in  soils,  by  promoting  certain  favorable  chemical  changes.  The 
condition  of  the  soil  also  influences  the  amount  of  available  pot- 
ash. Light  sandy  soils  are  more  apt  to  be  deficient  in  potash  than 
heavy  soils. 

Forms  of  Potash. — A  review  of  this  chapter  teaches  us  that 
potash  exists  chiefly  in  three  forms  in  fertilizer  materials. 

.       1  ,     -J     •        (    Muriate  of  potash 
As  chloride  m     j    gy,^.^.^ 

-     .         1   u  f    •       ^    Sulphate  of  potash 

As  sulphate  in    |    Double  sulphate  of  potash  and  magnesia. 

As  sulphate  and  chloride  in  Kainit  (action  same  as  chloride) 
C    Potassium-magnesium  carbonate 

As  carbonate  in  -s    Wood  ashes 

(    Potassium  carbonate. 

The  form  of  potash  is  an  important  consideration  in  the  pur- 
chase of  fertilizers,  as  potash  in  the  form  of  chloride  is  injurious 
to  the  marketable  value  of  certain  crops  as  tobacco,  potatoes, 
sugar  beets,  and  oranges.  Muriate  of  potash  seems  to  make 
potatoes  waxy ;  with  sugar  beets  it  seems  to  lessen  the  percentage 
of  sugar  as  sucrose ;  for  tobacco  the  flavor  is  spoiled  for  smoking 
it  sometimes  forms  calcium  chloride  in  the  soil  which  is  not  rel- 
ished by  plants. 

The  form  of  potash  does  not  seem  to  work  any  injury  on  crops 
as  legumes,  grasses,  corn,  etc.,  and  for  such  crops  potash  should 
be  purchased  in  its  cheapest  form.  Muriate  of  potash  diffuses 
better  in  the  soil  than  sulphate  of  potash.  It  should  be  under- 
stood that  actual  potash  (K2O)  is  not  injurious  to  plants,  but 
the  form  or  elements  it  is  associated  with  are  the  cause  of  its 
effect  on  crops. 

Fixation  of  Potash. — Potash  is  quickly  fixed  in  the  soil ;  it  re- 
places the  sodium  and  calcium  in  soils  and  forms  compounds  in- 
soluble in  water.  The  chlorides  of  potash  are  liable  to  render  the 
lime  content  of  a  soil  deficient,  as  the  chlorine  unites  with  lime 
and  forms  a  soluble  compound  that  is  readily  leached  from  the 


96  FERTILITY   AND   FERTILIZER    HINTS 

soil.  In  experiments  at  the  Massachusetts  Experiment  Station, 
Goessmann  found  that  continued  applications  of  muriate  of  pot- 
ash produced  sickly  crops  which  were  made  well  and  healthful  by 
an  application  of  lime.  Therefore  acid  soils  should  always  re- 
ceive an  application  of  lime  before  the  use  of  potash  as  chloride. 
As  potash  is  quickly  fixed  in  the  soil  and  the  chlorides  washed 
out,  it  is  often  advisable  to  apply  chloride  of  potash  some  time 
before  the  crop  is  planted,  especially  when  the  crop  that  is  to  be 
planted  is  injured  by  chlorine.  The  fixation  of  potash  usually 
occurs  in  the  surface  soil  and  so  rapidly  does  this  fixation  take 
place  on  some  alluvial  soils,  that  it  is  necessary  to  work  it  in  soon 
after  applying  to  insure  an  even  distribution. 

Functions  of  Potash. — The  intelligent  use  of  potash  fertilizers 
requires  a  knowledge  of  the  effect  of  this  constituent  on  crops. 
Potash  is  essential  to  the  formation  of  starch,  sugar  and  cellulose 
(pure  fiber)  in  plants.  When  there  is  a  deficiency  of  available 
potash  in  soils,  certain  plants  do  not  mature  well. 

Potash  Favors  Seed  and  Straw  Formation. — HalP  says :  On 
grass  plots  another  very  striking  effect  of  potash  manuring  is 
also  very  manifest.  On  the  potash-starved  plots  the  grasses  fail 
to  a  large  extent  to  develop  any  seed,  and  the  heads  are  soft  and 
barren,  presumably  because  of  the  deficiency  in  carbohydrate  for- 
mation. For  the  same  cause  the  straw,  not  only  of  the  grasses, 
but  also  on  the  similarly  manured  wheat  and  barley  plots,  is  also 
weak  and  brittle  when  potash  is  wanting. 

Potash  Effects  the  Leaves. — Grass  grown  on  soils  deficient  in 
potash  tends  to  show  the  effect  of  this  constituent  by  producing 
a  brown  sickly  appearance.  The  grass  blades  often  turn  brown 
about  2  inches  from  the  tip  and  die  off.  The  leaves  of  root  crops 
also  often  show  a  lack  of  potash  when  they  are  nearing  maturity, 
by  a  spotted  or  brown  coloration. 

Potash  Effects  Maturity. — Experiments  show  that  soils  without 
sufficient  potash  do  not  produce  as  valuable  grain  crops  in  dry 
seasons  as  soils  rich  in  this  constituent.  This  is  probably  due 
to  the  fact  that  potash  causes  a  longer  growing  period  and  holds 
back  maturity.     With   root  crops  the  opposite   effect   has  been 

'  Fertilizers  and  Manures. 


POTASH    FERTILIZERS  97 

found  to  exist.  That  is  the  maturity  of  these  crops  is  hastened 
by  a  supply  of  potash. 

Potash  Helps  to  Neutralize  Plant  Acids. — Many  plants  contain 
acids ;  for  example,  in  the  grape  there  is  tartaric  acid ;  in  the 
apple,  malic ;  in  the  orange,  citric ;  and  potash  helps  to  neutralize 
these  plant  acids  and  form  acid  salts. 

Potash  Sometimes  Checks  Insect  Pests  and  Plant  Diseases. — 
Experiments  show  that  certain  forms  of  potash  are  distasteful 
to  some  insects  and  tend  to  check  their  ravages.  Potash  seems 
to  make  plants  better  able  to  resist  attacks  of  certain  fungi,  es- 
pecially when  soils  are  deficient  in  this  constituent,  by  producing 
a  stronger  and  more  vigorous  growth.* 


CHAPTER  X. 


MISCELLANEOUS  FERTILIZER  MATERIALS. 

The  fertilizer  materials  discussed  in  the  previous  chapters  are 
those  products  most  commonly  used  and  constitute  the  main 
sources  of  nitrogen,  phosphoric  acid  and  potash.  There  are,  how- 
ever, other  substances  that  are  occasionally  utilized  that  have 
some  value.  Some  of  these  materials  are  used  at  times  by  ferti- 
lizer manufacturers  v^hile  others  are  employed  directly  by  farm- 
ers. Some  of  them  furnish  one  or  more  of  the  essential  ele- 
ments in  amounts  sufficient  to  warrant  their  use,  when  they  can 
be  obtained  cheaply,  while  others  are  not  applied  for  their  fer- 
tilizer value  but  to  improve  the  condition  or  texture  of  the  soil, 
to  increase  the  available  plant  food  supply  or  to  conserve  moisture. 
There  are  some  products  discussed  in  this  chapter  that  have 
no  particular  value  as  fertilizer  but  are  taken  up  to  set  clear 
impressions  that  are  prevalent  among  some  who  feel  that  these 
products  can  be  used  to  replace  to  a  certain  extent  the  more 
important  fertilizer  materials.  It  should  be  remembered  that 
many  of  these  materials  we  are  about  to  discuss  do  not  contain 
sufficient  amounts  of  the  essential  elements  to  produce  paying 
crops  but  they  may  be  used  to  partially  replace  commercial  fer- 
tilizers. 

Compost. — A  compost  is  usually  made  up  of  layers  of  manure 
and  vegetable  matter.  Sometimes  lime,  acid  phosphate,  ground 
raw  rock  phosphate,  cotton-seed,  gypsum,  and  similar  fertilizer 
materials  are  added  to  it.  A  compost  can  be  made  in  the  fol- 
lowing manner.  First  select  a  shady  place  and  provide  a  good 
drainage.  Then  make  a  foundation  with  a  layer  of  earth.  On 
top  of  this  place  a  layer  of  leaves  or  manure  then  a  layer  of 
earth,  another  layer  of  leaves,  cotton-seed  and  manure,  a  layer 
of  earth,  etc.  The  top  of  the  compost  should  be  covered  with 
earth  and  it  should  be  shaped  to  shed  water.  The  compost  should 
be  kept  moist  to  prevent  the  loss  of  nitrogen  as  ammonia.  The 
manure,  leaves,  cotton-seed,  raw  rock  phosphate,  etc.,  will  de- 
cay or  undergo  changes  due  to  the  action  of  organisms  similar 


MISCELLANEOUS  FERTILIZER   MATERIALS  99 

to  what  would  take  place  in  the  soil,  when  the  compost  is  kept 
thoroughly  moist.  Before  applying  any  of  the  compost  to  the 
land  it  should  be  well  mixed  to  make  it  uniform.  The  earth 
is  used  in  layers  to  absorb  the  ammonia  that  may  be  set  free  in 
the  process  of  decay  of  the  organic  materials.  The  amount  of 
fertilizing  material  obtained  from  a  compost  will  be  equal  to  the 
amount  of  fertilizer  material  added  to  it,  provided  there  is  no 
loss;  but  the  availability  of  these  materials  will  be  greater. 

Seaweed. — In  states  bordering  on  the  ocean  seaweed  is  used 
a  great  deal  for  fertilizer.  Stormy  weather  throws  considerable 
quantities  on  the  beach  and  the  states  of  Rhode  Island,  New  Jer- 
sey, New  Hampshire,  and  Massachusetts  have  used  this  fertilizer 
for  many  years. 

The  best  way  to  apply  seaweed  is  in  the  fresh  state.  The  differ- 
ent varieties  of  seaweed  contain  from  70  to  over  80  per  cent,  of 
moisture  and  when  it  is  to  be  transported  any  considerable  dis- 
tance it  may  be  spread  thin  and  sun-drie.d  to  avoid  carting  so 
much  water.  They  contain  from  0.25  to  1.25  per  cent,  of  ni- 
trogen, about  0.20  per  cent,  of  phosphoric  acid  and  0.60  to  1.4 
per  cent,  of  potash.  About  20  to  25  per  cent,  of  the  ash  of  sea- 
weeds is  chlorine.* 

Marl. — There  are  two  principal  classes  of  marls,  namely  shell 
marls  and  green  sand  marls.  The  shell  marls  contain  less  phos- 
phoric acid  and  potash  and  more  lime  than  the  other  marls. 
Marls  average  about  0.40  per  cent,  of  phosphoric  acid  and  1.40 
per  cent,  of  potash.  Marls  improve  the  physical  condition  of 
some  soils.* 

Peat  and  Muck. — In  low  wet  places  where  vegetable  matter 
accumulates,  decomposition  sets  in  and  the  substance  formed  is 
called  peat  or  muck.  This  material  does  not  run  high  in  the 
essential  elements;  it  averages  about  0.7  per  cent,  of  nitrogen  and 
about  75  per  cent,  of  water.  The  phosphoric  acid  and  potash  con- 
tents approximate  what  is  contained  in  good  soil.  The  value  of 
this  substance  depends  upon  its  nitrogen  content  which  in  turns 
depends  upon  the  amount  of  organic  matter.  The  nitrogen  is 
not  perhaps  as  available  as  that  in  cultivated  soils  and  unless  it 
is  easy  to  obtain  it  is  doubtful  whether  it  pays  to  use  it.* 


lOO  FERTILITY  AND  FERTILIZER   HINTS 

Pulverized  Manures. — Pulverized  sheep  manure,  poultry  ma- 
nure, and  pigeon  manure  are  found  on  the  market  in  some  sec- 
tions. These  manures  usually  carry  a  higher  price  than  the 
regular  commercial  fertilizers  although  they  are  not  so  valuable. 
These  products  should  be  saved  on  the  farm  but  it  will  hardly 
pay  to  purchase  them  unless  the  price  is  much  less  than  for  com- 
mercial fertilizers.  The  value  of  these  manures  is  often  ex- 
aggerated because  they  are  quick  acting.  They  are  to  be  found 
for  sale  in  seed  stores  and  are  purchased  generally  in  small 
amounts  by  those  having  small  gardens  or  house  plants.* 

Fresh  Fish  Scrap. — Farmers  living  near  the  sea  coast  use  a 
great  deal  of  fresh  fish  scrap  and  whole  fish.  This  material  con- 
tains nitrogen  and  phosphoric  acid  but  an  average  composition 
is  impossible  to  give  because  the  moisture  content  is  so  variable. 
The  main  value  in  fish  is  derived  from  the  nitrogen  they  contain. 
Lobster  shells,  mussels,  shrimp  waste  and  King  crab  are  other 
wastes  that  are  used  for  fertilizer.  These  are  economical  ferti- 
lizers when  they  can  be  had  for  nothing,  or  at  a  low  price,  pro- 
vided they  do  not  have  to  be  carted  a  great  distance.* 

Sewage  and  Sewage  Sludge. — Sewage  contains  about  0.40  per 
cent,  of  nitrogen,  0.27  per  cent,  of  potash,  0.85  per  cent,  of 
phosphoric  acid  and  75-80  per  cent,  of  water.  It  is  not  a  valu- 
able fertilizer  and  requires  either  ditches  or  porous  pipes  for  its 
proper  distribution  on  the  land. 

Sewage  sludge  is  a  product  obtained  by  precipitating  the  sus- 
pended matter  in  sewage  with  certain  chemicals  and  squeezing 
out  the  excess  of  water.  This  product  contains  from  0.60  to  2.3 
per  cent,  of  nitrogen,  0.60  to  2.3  per  cent,  of  phosphoric  acid  and 
traces  of  potash.     It  has  some  value  as  fertilizer.* 

Coal  ashes  sometimes  helps  to  improve  the  condition  of  certain 
soils.  This  material  does  not  contain  enough  of  the  essential  ele- 
ments to  be  valuable  as  fertilizer  but  its  indirect  action  may  help 
to  produce  better  physical  properties  in  soils.  This  material  is 
perhaps  more  valuable  for  walks  and  roads  than  for  fertilizer. 

Lime-kiln  Ashes. — When  lime  and  wood  are  burned  together 
in  making  quicklime  the  resulting  product  is  known  as  lime-kiln 


MISCELIyANEOUS  FERTILIZER   MATERIALS  10 1 

ashes.  This  product  is  richer  in  Ume  than  wood  ashes  and  it 
may  be  used  on  soils  requiring  lime  when  the  price  is  reasonable. 
It  averages  2  per  cent,  of  potash,  0.75  per  cent,  of  phosphoric  acid 
and  40  per  cent,  of  lime."'= 

Rice  Hull  Ashes. — In  the  rice  sections  the  rice  hulls  are  often 
used  as  fuel  in  the  boilers  of  rice  mills.  This  product  contains 
about  1.2  per  cent,  of  potash,  and  0.6  per  cent,  of  phosphoric  acid. 

Corn  Cob  Ashes. — In  certain  sections  of  the  country  corn  cobs 
are  sometimes  used  in  place  of  wood  for  fuel.  This  product 
carries  about  7  per  cent,  of  potash,  2.4  per  cent,  of  phosphoric 
acid  and  1 1  per  cent,  of  lime.  It  is  evident  that  these  ashes  are 
valuable  for  soils  in  need  of  potash.  It  also  contains  an  appreci- 
able amount  of  phosphoric  acid.  Farmers  burning  corn  cobs  will 
do  well  if  they  save  these  ashes  and  apply  them  to  their  land. 

Brick  kiln  ashes  are  sometimes  used  for  fertilizer.  The  kind 
of  wood  burned  in  brick  kilns  will  influence  the  value  of  these 
ashes.  They  are  worth  purchasing  by  those  living  near  brick 
kilns  who  wish  to  apply  lime,  when  they  can  be  purchased  right. "^^ 

Soot  is  the  black  deposit  that  collects  in  flues  and  chimneys 
when  coal  or  wood  is  burned  and  is  used  in  England  quite  ex- 
tensively as  fertilizer.  Soot  from  coal  averages  about  3  per  cent, 
of  nitrogen  in  the  form  of  ammonia.  It  is  more  valuable  in  im- 
proving the  physical  condition  of  soils  than  as  a  fertilizer.  Its 
dark  color  increases  soil  temperature  by  absorbing  the  rays  of 
the  sun,  thus  helping  plant  growth  and  the  action  of  the  soil 
organisms.  It  lightens  heavy  soils  and  is  not  relished  by  certain 
insects  that  damage  crops.* 

Street  sweepings  are  sometimes  used  by  gardeners.  When  they 
contain  a  large  proportion  of  horse  manure  they  may  have  a  little 
value.  However  the  liquid  portions  are  not  saved  so  that  they 
are  not  as  valuable  as  farm  manure.  Street  sweepings  usually 
contain  other  debris  than  horse  manure  which  of  course  de- 
creases their  value.  Generally  speaking,  street  sweepings  should 
not  be  used  unless  the  expense  of  hauHng  is  very  small.  Most 
people  would  not  care  to  utilize  this  waste  because  of  the  un- 
sanitary nature  of  it.  Debris  from  houses  etc.  are  liable  to  con- 
taminate it  in  which  case  it  would  not  be  a  safe  fertilizer. 


I02  FERTILITY  AND  FERTILIZER   HINTS 

Potassium  nitrate,  or  saltpeter,  contains  from  12  to  13  per 
cent,  of  nitrogen  and  40  to  45  per  cent,  of  potash.  It  is  an 
excellent  fertilizer  but  the  market  price  prohibits  its  general  use.* 

Anunonium  nitrate  is  a  rich  nitrogenous  salt  but  it  is  too  ex- 
pensive to  employ  for  fertilizing  purposes. 

Silicate  of  Potash. — Some  minerals  as  feldspathic  rock  contain 
considerable  amounts  (12  to  15  per  cent,  and  more)  of  potash. 
These  potash  feldspars  have  been  ground  to  a  powder  and  put 
upon  the  market  for  fertilizer  from  time  to  time.  Experiments 
show  this  material  to  be  of  very  low  crop  producing  value.* 

Iron  sulphate  is  produced  quite  extensively  as  a  by-product  in 
the  manufacture  of  steel.  Although  iron  is  necessary  for  plant 
growth  most  plants  do  not  use  more  than  15  pounds  of  iron  oxide 
per  acre  and  average  soils  contain  15  tons  of  this  material  per 
acre  in  the  surface  soil  to  a  depth  of  9  inches.  So  it  is  evident 
that  soils  contain  abundant  amounts  of  iron  for  the  needs  of 
plants. 

Common  salt,  or  sodium  chloride,  has  been  used  for  many  years 
in  some  of  the  older  countries  as  a  fertilizer.  In  this  country  a 
product  called  agricultural  salt  has  been  on  the  market,  which  is 
mainly  common  salt.  Most  of  our  soils  are  rich  enough  in 
sodium  so  that  applications  of  common  salt  are  not  necessary. 
This  material  does  not  furnish  any  nitrogen,  phosphoric  acid  or 
potash.* 

Powder  waste  is  another  product  that  is  principally  made  up 
of  common  salt.  Some  of  this  material  may  contain  nitrates  in 
which  case  it  is  more  valuable  than  common  salt,  although  it 
should  not  be  considered  unless  it  can  be  had  for  nothing,  or 
very  cheap.  It  should  be  applied  in  small  quantities  because  of 
the  deleterious  action  that  large  applications  of  sodium  chloride 
have  on  vegetation. 

Sulphates  of  Soda  and  Magnesia. — The  use  of  either  sulphate 
of  soda  or  magnesia  is  hardly  to  be  considered  on  American  soils 
except  when  some  special  crop  is  grown  that  depletes  the  soil 
of  them,  which  is  indeed  very  rarely.  When  fertilizers  are  Used 
there  is  enough  of  these  constituents  supplied  for  the  needs  of 


MISCKLLANKOUS   FKRTILl/'.KR    MATKRIALS  103 

the  crop.  Most  of  our  soils  are  well  furnished  with  these  con- 
stituents. Coninion  salt  is  cheaper  than  sulphates  of  soda  or 
magnesia  and  when  needed  will  serve  the  same  purpose,  namely, 
to  render  potash  available.'^ 

Carbonate  of  magnesia  is  sometimes  found  on  the  market  but 
carbonate  of  lime  performs  the  same  functions  except  that  mag- 
nesia is  not  supplied,  so  that  we  need  not  consider  this  material 
in  our  fertilizer  problems. 

Ammonium  chloride  and  ammonium  carbonate  are  not  good 
fertilizers  because  they  injure  plants.  Ammonium  chloride  is 
sometimes  called  sal-ammoniac  and  in  the  pure  state  it  is  rather 
expensive. 

Manganese  Salts. — Manganese  is  found  in  small  amounts  in 
plants  and  it  is  said  to  stimulate  their  growth.  This  element 
is  not  necessary  to  apply  as  soils  contain  enough  of  it  to  satisfy 
the  wants  of  the  plant. 


CHAPTER  XI. 

LIME,  GYPSUM  AND  GREEN  MANURES. 

Lime  has  been  used  for  agricultural  purposes  for  many  cen- 
turies, but  for  how  long  we  do  not  know.  Records  show  that  it 
was  used  on  land  before  the  Christian  Era.  During  the  sixteenth 
and  seventeenth  centuries  the  practice  of  liming  the  land  was 
common  in  Great  Britain  and  at  that  time  lime  was  one  of  the 
principal   fertilizers  and  large  applications  were  often  supplied. 

Forms  of  Lime. — Lime  is  obtained  by  burning  limestone,  chalk, 
or  shells.  These  are  all  substances  rich  in  carbonate  of  lime 
(CaCOs).  When  they  are  burned  the  carbonic  acid  (CO2) 
passes  off,  leaving  the  oxide  of  lime  (CaO) ,  which  is  called  quick- 
lime, caustic  lime,  store  lime  and  burned  lime.  The  oxide  of 
lime  is  usually  known  as  lime.  When  water  is  added  to  this  pro- 
duct it  is  readily  absorbed  and  high  heat  develops  forming  hy- 
drate of  lime  (Ca[OH]2)  which  crumbles  to  a  powder.  This 
is  known  as  slaked  lime.  Quicklime  readily  absorbs  water  and 
therefore  slakes  when  exposed  to  the  air.  This  is  known  as  air 
slaked  lime  and  is  not  as  completely  slaked  as  when  treated  with 
water.  Quicklime  is  apt  to  change  to  limestone  on  standing  as 
it  absorbs  carbonic  acid  from  the  atmosphere.  When  quicklime 
is  applied  to  the  soil  it  changes  to  carbonate  of  lime. 

One  hundred  pounds  of  limestone  make  about  50  to  56  pounds 
of  quicklime  which  produce  about  75  to  85  pounds  of  water 
slaked  lime.  The  purer  the  limestone,  the  more  quicklime  and 
water  slaked  lime  are  obtained.* 

When  Soils  Need  Lime. — A  certain  amount  of  calcium  carbonate 
should  be  present  in  soils  as  this  compound  helps  to  make  plant 
food  available  and  keeps  the  soil  in  a  condition  favorable  for  pro- 
ducing crops.  When  there  is  a  deficiency  of  calcium  carbc-nate, 
the  soil  will  most  likely  be  acid  or  sour.  ■Most  farm  crops  do  not 
grow  well  on  sour  soils,  but  certain  weeds  seem  to  thrive  on 
them,  and  so  it  is  important  to  keep  soils  sweet  or  stocked  with  a 
sufificiency  of  carbonate  of  lime.  The  addition  of  ordinary  fer- 
tilizers will  not  benefit  crops  on  sour  soils  because  the  nitrifying 


LIMi:^    GYPSUM    AND    GRKKN    MANURUS  I05 

organisms  cannot  work  to  advantage  in  an  acid  niodiuin.  'JMicre 
may  be  an  ample  supply  of  nitrogen,  phosphoric  acid  and  potash 
in  a  sour  soil  and  yet  good  crops  cannot  be  produced  because  of 
the  need  of  lime.  Soils  that  run  as  low  as  0.2  per  cent,  of  calcium 
carbonate  generally  need  lime. 

How  to  Find  Out  "When  Soils  are  Acid. — A  simple  method  that 
is  often  effective  consists  of  testing  the  soil  with  blue  litmus 
paper.  A  few  cents  worth  of  this  paper  may  be  purchased  at  a 
drug  store.  Test  the  soil  as  follows :  Collect  some  earth  from 
those  portions  of  the  field  where  the  plants  are  poor  or  sickly. 
JNIix  the  samples  of  earth  together,  take  a  small  portion  and  add 
water  to  form  a  paste.  Place  one  end  of  the  litmus  paper  in  this 
mixture  and  let  it  remain  for  about  45  minutes.  If  the  soil  is 
sufificiently  acid  the  color  of  that  part  of  the  litmus  paper  which 
was  dipped  in  the  paste  will  be  changed  to  red.  This  is  not  a 
delicate  test  and  is  only  an  indication  of  a  soil  badly  in  need  of 
lime.  Another  way  to  find  out  whether  your  soil  needs  lime  is  to 
express  about  one-half  a  pound  of  the  suspicious  soil  to  your 
State  Experiment  Station  requesting  them  to  find  out  if  your 
soil  needs  lime.  Or  a  plot  of  the  suspicious  land  may  be  spread 
with  a  liberal  application  of  lime  and  the  efifect  on  the  crop  noted. 
This  last  method  is  perhaps  the  best  test. 

How  to  Apply  Lime. — Finely  ground  limestone,  quick  lime,  or 
water  slaked  lime  may  be  used  to  correct  acidity  in  soils.  If 
water  slaked  lime  is  used  it  should  be  applied  just  as  soon  as  it 
becomes  powdered.  If  quicklime  is  preferred,  it  may  be  dumped 
into  small  heaps  and  kept  covered  with  earth  until  the  lime  slakes 
or  crumbles. 

Lime  should  be  spread  in  a  thin  even  layer  and  harrowed  in. 
If  slaked  lime  is  used  it  should  be  harrowed  in  immediately  as  it 
changes  to  the  carbonate  form  on  exposure  to  the  air.  Some 
farmers  use  a  lime  spreader  which  machine  is  very  effective. 
Lime  should  be  applied  some  time  before  planting  as  it  is  liable 
to  injure  the  seed. 

The  Form  of  Lime  to  Use.— Marble  dust,  ground  limestone, 
ground   oyster   shells,    etc.    (calcium   carbonate),   are   preferable 


Io6  FERTILITY   AND  FERTILIZER   HINTS 

for  soils  rich  in  organic  matter,  to  prevent  the  loss  of  nitrogen. 
Should  you  desire  to  correct  the  acidity  of  a  soil  and  decompose 
the  organic  matter  quickly,  caustic  lime  or  slacked  lime  should  be 
used.  On  peaty  land,  old  forest  land,  and  other  places  where 
considerable  vegetable  matter  has  accumulated,  lime  is  very 
beneficial  as  it  helps  to  liberate  the  nitrogen  and  form  nitrates.* 

Amount  of  Lime  to  Apply. — The  nature  of  the  soil  regulates  to 
a  certain  extent  the  amount  of  lime  to  apply.  On  soils  that  are 
acid  it  should  be  understood  that  the  rains  have  carried  the 
acidity  to  the  subsoil.  Therefore  during  dry  periods  the  capillary 
water  will  bring  up  acid  from  the  subsoil.  Enough  lime  should 
be  added  to  correct  the  acidity  of  the  surface  soil  and  allowance 
should  be  made  for  that  which  may  be  brought  up  from  the  sub- 
soil. A  small  application  will  not  last  as  long  as  a  large  quantity 
but  will  in  all  probability  give  greater  profits  per  ton  of  lime. 
If  land  must  be  improved  quickly,  large  applications  are  the  most 
desirable.  The  nature  of  the  crops  grown  should  also  determine 
the  amount  of  lime  to  use.  On  sandy  soils  800  to  1,000  pounds 
of  slaked  lime  or  1,600  to  2,000  pounds  of  ground  limestone 
per  acre  should  prove  sufficient  and  for  heavy  clay  soils,  1,600 
to  2,000  pounds  of  slaked  lime  or  3,000  to  4,000  pounds  of 
ground  limestone  per  acre  will  prove  beneficial.  Sometimes 
smaller  or  larger  amounts  are  used  with  good  results.  Some 
farmers  use  light  applications  every  four  or  five  years  while 
others  apply  large  quantities  at  eight,  ten  or  fifteen  year  periods. 
The  farmer  should  be  the  best  judge  and  he  can  find  out  after  one 
trial  the  amount  of  lime  necessary  to  satisfy  his  conditions  and 
when  to  apply  it.* 

Legumes  Require  an  Alkaline  Soil. — It  is  a  well  known  fact  that 
alfalfa,  clovers,  etc.,  require  a  soil  well  supplied  with  lime  for 
the  best  returns.  One  has  only  to  visit  an  alfalfa  field  in  a  lime- 
stone section  to  find  out  the  benefit  of  an  alkaline  soil  for  produc- 
ing leguminous  crops.  On  acid  soils  the  legumes  become  sickly 
and  do  not  develop  tubercles  or  nodules  on  their  roots.  These 
helpful  bacteria  which  gather  nitrogen  from  the  air  are  not  active 
in  an  acid  soil  and  cannot  perform  their  functions. 


LIMK,    GVPSUM    AND    GRHEN     MANURKS  I07 

Mechanical  Action  of  Lime. — On  a  heavy  clay  soil  lime  loosens 
the  soil  and  makes  it  lighter  and  more  porous.  It  relieves  some- 
what the  tendency  of  these  soils  to  puddle.  It  renders  them  easier 
to  work  and  lessens  the  stickiness  or  adhesiveness  a  great  deal. 
We  learned  that  puddling  is  due  to  the  fine  state  of  division  of  the 
particles  in  clay  soils.  Lime  tends  to  cause  a  coagulation  or  floccu- 
lation  of  these  fine  soil  particles.  This  action  is  easily  demon- 
strated by  placing  some  clay  soil  in  a  glass  of  water  and  adding  a 
pinch  of  lime.  When  the  lime  is  added  and  the  contents  of  the 
glass  well  stirred,  the  soil  particles  precipitate  and  settle  to  the 
bottom  of  the  glass  leaving  a  clear  solution  of  water. 

Lime  lessens  the  tendency  of  clay  soils  from  cracking  because 
it  does  not  shrink  in  dry  weather.  For  this  reason  the  addition 
of  lime  to  clay  soils  makes  them  easier  to  work.  On  sandy  soils 
lime  has  an  entirely  opposite  eflfect  than  on  clay  soils.  Instead  of 
making  the  soil  lighter  and  more  open  it  binds  together  the  soil 
particles.  It  increases  the  capillary  power  of  light  soils  and  thus 
m.akes  these  soils  better  able  to  stand  dry  weather. 

Lime  does  not  add  any  nitrogen,  phosphoric  acid  or  potash  to 
the  soil  but  sets  these  constituents  free.  Therefore  the  continual 
use  of  lime  will  make  a  soil  less  productive,  hence  the  saying, 
"Liming  makes  the  father  rich  and  the  son  poor." 

Lime  Decreases  Many  Fungus  Diseases. — Many  fungi  and  moulds 
that  prosper  in  an  acid  soil  are  destroyed  when  lime  is  added  and 
the  soil  kept  alkaline  or  sweet.  Certain  rusts,  smuts,  club  root, 
etc.,  are  due  to  fungi  that  require  a  sour  soil  for  their  develop- 
ment. Lime  seems  to  favor  the  potato  scab  fungus  and  potatoes 
grown  on  limed  soils  usually  produce  scabby  tubers.  This  fungus 
may  be  checked  in  alkaline  soils  by  dipping  the  seed  potatoes  in 
a  solution  of  formalin  or  corrosive  sublimate  before  planting.* 

Gas  lime  is  the  refuse  lime  from  the  manufacture  of  coal  gas. 
Coal  gas  is  passed  over  fresh  slaked  lime  which  absorbs  the  im- 
purities, principally  sulphur  compounds  and  gases,  from  the  coal 
gas.  The  presence  of  sulphur  compounds  in  this  product  makes 
it  unsafe  to  use  because  it  has  a  poisonous  effect  on  young  plant 
growth.     It  may  be  applied  to  the  soil  provided  it  is  allowed  to 


I08  FERTII.ITY   AND   FERTILIZER    HINTS 

thoroughly  oxidize  (by  exposing  it  to  the  air  for  a  long  time 
in  heaps  mixed  with  earth)  in  which  case  the  injurious  com- 
pounds are  changed  so  that  they  are  not  harmful.  Sometimes  it 
is  put  on  the  land  before  being  oxidized  to  get  rid  of  insects  and 
if  so  it  should  be  applied  a  long  time  before  planting.* 

Gypsum. — This  product  is  sometimes  called  land  plaster.  The 
lime  is  as  sulphate  in  this  compound.  Gypsum  does  not  contain 
as  much  lime  as  good  limestone.  It  is  a  good  fertilizer  for 
leguminous  crops  as  clover,  alfalfa,  etc.  The  use  of  gypsum  in- 
stead of  lime  (CaO)  is  not  to  be  recommended  as  the  real  value 
of  gypsum  is  in  liberating  locked-up  potash.  Super-phosphates 
contain  gypsum  and  when  they  are  used  it  would  not  be  necessary 
to  apply  gypsum.  Gypsum  seems  to  keep  the  soil  moist  in  dry 
weather  by  absorbing  moisture  from  the  air  or  conserving  it  in 
the  soil.  On  soils  low  in  potash,  gypsum  does  not  seem  to  be 
beneficial  and  when  soils  fail  to  respond  to  gypsum  an  application 
of  potash  may  be  needed.* 

Green  Manures. — Any  crop  that  is  grown  and  plowed  under  in 
order  to  benefit  the  soil  is  called  a  green  manure.  A  green 
manure  may  help  the  soil  in  any  of  the  following  ways : 

1.  By  keeping  up  the  humus  supply  by  furnishing  organic 
matter. 

2.  By  improving  the  texture  of  soils,  by  making  heavy  soils 
lighter  and  sandy  soils  more  retentive. 

3.  By  utilizing  the  soluble  plant  food  that  would  otherwise  be 
lost  if  the  land  was  left  bare. 

4.  By  ridding  the  land  of  many  weeds  and  thus  serve  as  a 
cleaning  crop. 

5.  By  bringing  up  plant  foi^l  from  the  subsoil  to  the  surface 
soil. 

6.  By  using  a  leguminous  crop  the  nitrogen  content  of  the  soil 
may  be  increased,  by  utilizing  the  nitrogen  from  the  air.  ' 

7.  By  preventing  the  washing  of  soils,  or  erosion. 

Classes  of  Green  Manures. — There  are  many  crops  used  as  green 
manures  and  the  section  of  the  country  determines  to  a  great  ex- 


I,IME,    GYPSUM    AND    GREEN    MANURES  IO9 

tent  what  crops  to  select.     Green  manure  crops  may  be  classified 
as  leguminous  and  non-leguminous. 

1,  The  leguminous  green  manure  crops  are  those  that  have  the 
power  of  securing  nitrogen  from  the  air  and  are  represented  in 
the  clovers,  cowpea,  soy  bean,  alfalfa,  vetches,  velvet  bean, 
Canada  field  pea,  etc. 

2.  The  non-leguminous  green  manure  crops  are  those  that 
draw  on  the  soil  entirely  for  their  supply  of  food,  and  rape,  rye, 
oats,  buckwheat  and  mustard  are  examples  of  this  class. 

Of  the  leguminous  crops  the  red  clover  is  the  most  popular  in 
the  North  and  the  cowpea  and  clovers  in  the  South.  Crimson 
clover  and  alfalfa  are  also  popular.  The  vetches  and  soy  beans 
are  not  used  so  much  as  the  other  mentioned  legumes. 

Rye  is  the  most  common  non-leguminous  crop  and  is  often 
pastured  in  the  fall  or  early  winter. 

Leguminous  Crops  are  to  be  Preferred. — The  leguminous  crops 
are  better  than  the  non-leguminous  because  they  can  secure 
nitrogen  from  the  air  and  increase  the  soil  supply  of  this  con- 
stituent. They  also  return  more  nitrogen  to  the  soil  when  plowed 
under.  The  non-leguminous  plants  simply  draw  on  the  soil 
for  food  and  when  plowed  under  only  add  non-nitrogenous  matter. 
The  principal  benefit  derived  from  the  non-leguminous  plants  is 
to  save  the  loss  of  soluble  plant  food  when  a  legume  cantiot  be 
selected.  The  non-leguminous  plants  are  more  expensive  to 
grow  because  they  require  a  supply  of  nitrogen  and  generally  of 
phosphoric  acid  and  potash  to  insure  good  growth.  The  legumes 
only  require  potash  and  phosphoric  acid  and  sometimes  only 
phosphoric  acid.  So  it  is  evident  that  rye,  oats,  rape,  mustard, 
etc.,  cannot  take  the  place  of  the  legumes  in  supplying  green 
manure  as  they  cost  too  much  to  grow  and  do  not  return  as  much 
fertility  to  the  soil.* 

The  Best  Time  to  Plow  Under  a  Green  Manure. — Crops  used  for 
green  manuring  should  be  plowed  under  before  they  become  dry. 
When  they  are  plowed  under  while  green  and  fresh  they  are  more 
readily  decayed  and  prevent  the  loss  of  water  somewhat  from 
light  soils.  Dry  crops  plowed  under  interfere  with  the  use  of 
water  from  the  subsoil  and  on  light  sandy  soils  may  lower  the 


no  FERTILITY   AND  FERTILIZER    HINTS 

yield  of  the  crop  that  follows.  If  possible  the  green  mnnure 
should  be  plowed  under  some  two  or  three  weeks  before  planting 
time  to  give  it  a  chance  to  partially  decay  so  as  not  to  injure  the 
planted  crop  and  to  furnish  some  food  for  the  young  seedlings. 
The  Best  Time  to  Grow  a  Green  Manure. — If  the  soil  is  poor 
and  run  down  it  is  sometimes  advisable  to  keep  it  in  a  green 
manure  for  a  season  or  two.  Generally,  however,  green  manures 
fit  well  into  rotations  and  mav  often  be  grown  when  the  land  is 


Fig. 


-Pear  orchard  with  cover  crop. 


ordinarily  idle  or  between  money  crops.  In  the  South,  crops  like 
rye,  crimson  clover,  red  clover,  vetch,  etc.  may  be  grown  in  the 
winter  and  turned  under  in  time  for  the  summer  crop.  In  the 
North,  rye  and  vetch  may  be  used  as  winter  crops.  Sometimes 
it  is  advisable  to  sow  a  green  manure  at  the  time  another  crop  is 
laid  by.     Then  when  the  crop  is  harvested  the  green  manure  crop 


UME,    GVI'SUM    AND    GRKKN     MANURES  III 

will  have  grown  sufficiently  to  turn  under  and  the  land  may  be 
sowed  to  some  small  grain  crop ;  or  the  green  manure  crop  may 
be  planted  after  harvest  and  remain  on  the  land  all  winter  and 
plowed  under  in  the  spring. 

In  fruit  orchards  green  manure  crops  (cover  crops)  as  rye. 
oats,  clover,  etc.,  are  often  sown  about  mid-summer  to  absorb 
moisture  and  available  plant  food  from  the  soil  and  to  cause  the 
buds  to  mature  and  cease  growth  of  the  wood  and  leaves.  This 
crop  is  allowed  to  remain  on  the  soil  all  winter  and  in  the  spring 
it  is  plowed  under.  By  keeping  the  land  covered  during  the 
winter  leaching  of  plant  food  and  washing  away  of  soil  is 
lessened. 

Deep  Rooted  Plants  Valuable. — Alfalfa,  clover,  etc.,  have  very 
long  tap  roots  which  penetrate  the  subsoil,  thus  securing  a  great 
deal  of  plant  food  that  would  not  be  within  reach  of  many  culti- 
vated plants.  These  leguminous  plants  also  bring  a  great  deal  of 
plant  food  from  the  subsoil  to  the  surface  soil  and  leave  it  there 
for  succeeding  crops.  When  these  deep  roots  decay  they  leave 
openings  in  the  soil  which  help  to  increase  drainage  and  aera- 
tion and  thus  improve  the  physical  condition  of  soils. 


CHAPTER  XII. 


COMMERCIAL  FERTILIZERS. 

Since  i860,  when  fertilizers  were  used  on  a  comparatively 
small  scale,  the  fertilizer  industry  has  increased  until  to-day  it  is 
of  great  importance.  In  i860  the  wholesale  cost  of  the  output  of 
the  fertilizer  factories  was  $891,344,  in  1890,  $39,180,844,  in  1900. 
$40,445,661  and  in  1905,  $50,506,294  or  a  difference  of 
$49,614,950  between  the  years  i860  and  1905.  These  figures  do 
not  represent  what  the  consumer  paid  for  fertilizer  during  these 
years  as  these  amounts  cover  practically  the  wholesale  cost.  The 
above  figures  are  only  approximate  at  the  best  and  in  all  prob- 
ability they  should  be  larger  for  the  years  1900  and  1905,  but  they 
will  serve  to  impress  one  with  the  magnitude  of  the  fertilizer  in- 
dustry in  the  United  States  to-day.* 

Causes  for  the  Large  Consumption  of  Fertilizers. — The  causes 
for  the  large  and  increasing  use  of  commercial  fertilizers  are 
many.  Single  crop  farming  has  caused  many  farms  to  run  down 
in  fertility.  Many  crops  have  been  principally  raised.  Legumes 
have  been  grown  occasionally  or  not  at  all.  Green  manuring  has 
not  been  practiced  enough.  Poor  drainage  has  caused  losses 
of  fertility.  Some  farms  have  lost  much  of  their  fertile  soil  by 
erosion.  Farm  manure  has  not  always  been  saved  and  when  saved 
it  has  not  been  preserved  properly.  According  to  Bulletin  140 
by  the  Kentucky  Experiment  Station,  it  is  estimated  that  the 
annual  production  of  farm  manure  in  the  United  States  is  equal 
in  value  to  the  corn  crop  at  $1.05  per  bushel,  or  nearly  two  and 
one-half  billions  of  dollars.  The  most  conservative  estimate 
would  put  the  waste  of  farm  manure  at  one-third,  an  annual  loss 
of  about  $800,000,000.00.  This  is  about  eight  times  the  amount 
spent  annually  in  this  country  for  commercial  fertilizers.  There 
is  little  wonder  that  so  much  of  our  soil  is  becoming  unproductive. 
The  crops  have  also  been  sold  away  from  the  farm  instead  of  be- 
ing fed  to  live-stock.  Cover  and  catch  crops  have  not  always 
been  grown.  To  sum  up,  we  may  say  that  the  fertility  of  the 
soil  has  not  been  maintained,  and  farms  that  formerly  yielded 


COMiMKRCIAL    FliKTlLl/.KKS  113 

profitable  crops  with  applications  of  200  pounds  of  commercial 
fertilizer  per  acre,  now  require  400  to  600  pounds  and  sometimes 
800  to  1,200  pounds  to  produce  the  same  results. 

With  the  market  gardener  and  trucker  conditions  are  different. 
The  demand  for  vegetables  in  our  large  cities  has  caused  the 
market  gardener  in  the  north  and  the  trucker  in  the  south  to  use 
heavy  applications  of  fertilizers  to  produce  profitable  crops. 
Many  of  these  crops  are  heavy  feeders  and  require  to  be 
marketed  or  shipped  as  early  as  possible,  as  a  few  days  often 
means  a  great  difference  in  the  prices  received,  and  so  high 
priced  quick  acting  fertilizers  are  generally  used.  The  truckers 
are  often  located  on  sandy  soils  of  low  fertility  that  must  have 
plenty  of  fertilizer  to  produce  money  crops.  The  market  gardener, 
who  usually  lives  near  or  in  a  city  or  town,  produces  crops  on 
lands  that  would  bring  a  high  price  for  building  and  other 
purposes,  and  can  hardly  ever  afford  to  allow  his  land  to  be  idle 
or  to  be  sowed  to  some  soil  improving  crop,  but  must  have  a 
money  crop  growing  continually.  The  market  gardener  cannot 
afford  to  raise  live-stock  on  such  high  priced  land.  So  with  the 
market  gardener  and  trucker  the  consumption  of  fertilizer  will 
increase  with  the  demand  for  their  products,  and  as  the  popula- 
tion of  this  country  is  increasing  every  year  we  may  expect  more 
artificial  fertilizers  to  be  used  in  producing  market  garden  and 
truck  crops.  With  these  farmers,  and  especially  the  market 
gardener,  the  use  of  large  quantities  of  commercial  fertilizers  is  a 
necessity. 

How  the  General  Farmer  May  Lessen  the  Use  of  Commercial 
Fertilizers. — The  consumi^tion  of  commercial  fertilizers  may  be 
reduced  a  great  deal  by  many  farmers.  A  better  system  of  farm- 
ing should  be  adopted.  A  rational  rotation  system  including 
money  crops  and  soil  improving  crops  should  be  practiced.  Leg- 
umes should  be  included  whenever  possible  in  rotations  to  add 
to  the  supply  of  nitrogen  and  organic  matter  in  the  soil.  Live- 
stock should  be  kept  and  the  farm  crops  marketed  through  them. 
In  this  way  a  two-fold  or  full  value  will  be  obtained,  namely,  the 
feeding  and  fertilizer  values.  Farm  manure  should  be  saved 
and  preserved.     It  should  be  saved  to  supply  humus  and  fertility 


114  FERTILITY    AND    FERTILIZER    HINTS 

to  the  soil  and  it  should  be  preserved  to  prevent  losses  of  the 
essential  elements  by  fermentation  and  leaching.  The  land 
should  be  well  drained  and  tilled.  Crops  should  occupy  the 
land  continually.  Erosion  must  be  prevented.  Use  commercial 
fertilizers  only  to  supplement  the  organic  matter  and  those  con- 
stituents which  should  be  contained  in  the  soil.  Fertilizers  are 
not  expected  to  produce  crops  alone,  unless  increased  amounts 
are  used  every  year.  This  is  well  illustrated  by  an  experiment 
conducted  at  the  Louisiana  Experiment  Station  on  corn.  For 
four  years  commercial  fertilizer  only  was  applied  to  one  plot 
and  legumes  and  farm  manure  was  used  on  another  plot.  The 
yield  on  the  plot  receiving  commercial  fertilizer  alone,  showed 
12  bushels  per  acre  and  that  on  the  plot  receiving  organic  matter, 
52  bushels,  at  the  end  of  four  years. 

Fertilizing  Materials  Used  by  Manufacturers. — The  fertilizing 
materials  described  in  the  previous  chapters  are  those  that  the 
manufacturers  draw  on  for  making  their  mixtures.  The  farmer 
generally  purchases  his  fertilizer  in  the  mixed  state  under  some 
brand  name,  as  Corn  Fertilizer,  B.  C.  Brand,  etc.,  which  does  not 
indicate  the  materials  of  which  it  is  composed.  The  fertilizer 
materials  usually  predominate  in  one  constituent  while  the  manu- 
factured fertilizers  show  usually  two  or  three  of  the  constituents, 
as  nitrogen,  phosphoric  acid  and  potash.  The  manufacturers  may 
employ  materials  that  furnish  large  amounts  of  a  particular  con- 
stituent, as  nitrate  of  soda,  sulphate  of  ammonia,  dried  blood, 
sulphate  of  potash,  muriate  of  potash,  kainit,  and  Tennessee  or 
Florida  rock  phosphate.  He  may  choose  some  high  grade 
materials  as  those  just  mentioned  and  some  low  grade  materials 
as  beet  refuse,  leather  preparations,  low  grade  cotton-seed  meal, 
soluble  hair  and  wool  waste,  low  grade  bone-meal,  etc.  So  when 
a  mixed  fertilizer  reaches  the  farmer  the  identity  of  the  materials 
of  which  it  is  composed  is  not  known.* 

Basis  of  Purchase  of  Fertilizers. — There  are  two  systems  used 
in  purchasing  fertilizers,  namely,  the  unit  system  and  the  ton 
system. 

I.  The  Unit  System. — A  unit  is  20  pounds  or  one  per  cent,  of  a 
ton.     Manufacturers  and  dealers  in   fertilizer  materials  use  the 


COMMKKCIAL    FKRTILIZHUS  II5 

unit  system  almost  entirely.  Tankage,  bone  products,  blood, 
azotin,  steamed  horn  and  hoof  meal,  potash  salts,  nitrogenous 
salts,  superphosphates,  dry  ground  fish,  raw  rock  phosphates, 
cotton-seed  meal,  castor  pomace,  etc.,  are  all  purchased  on  the 
unit  basis.  For  example,  muriate  of  potash  will  be  quoted  at  80 
cents  a  unit.  This  means  that  the  actual  potash  in  muriate  of 
potash  will  cost  80  cents  for  20  pounds,  or  4  cents  for  one  pound. 
Dried  blood  perhaps  will  be  quoted  at  $3.30  per  unit  of  nitrogen. 
This  means  that  20  pounds  of  nitrogen  in  dried  blood  will  cost 
$3.30,  or  i6j/2  cents  for  one  pound. 

In  the  unit  system  of  purchasing  and  selling,  the  buyer  and 
seller  usually  employ  a  competent  neutral  chemist  to  draw  a 
representive  sample  of  the  material  and  settlement  is  made  on 
the  chemist's  findings.  This  is  indeed  an  excellent  system  because 
the  buyer  pays  for  just  what  is  present  in  the  material  and  the 
seller  receives  compensation  for  what  his  product  contains.  It 
may  be  said  that  this  system  is  very  satisfactory  to  the  fertilizer 
trade. 

2.  The  ton  basis  of  purchase  is  the  one  commonly  used  by  the 
manufacturer,  dealer,  etc.,  in  selling  to  the  consumer.  The  pro- 
ducts, both  mixed  and  unmixed,  are  sold  to  the  consumer  at  a 
fixed  price  per  ton  of  2,000  pounds.  This  system  is  not  as 
satisfactory  as  the  unit  system  because  the  purchaser  does  not 
always  receive  a  stipulated  amount  of  the  constituents  contracted 
for.  To  be  sure,  the  manufacturers  guarantee  their  products 
to  contain  given  amounts  of  fertilizer  constituents  and  aim  to 
meet  or  even  to  exceed  their  guarantees,  but  sometimes  the 
fertilizers  do  not  reach  them  in  every  particular.  The  prices  of 
the  fertilizers  sold  on  the  ton  basis  to  the  consumer  do  not  usually 
fluctuate  with  the  market,  as  the  manufacturer  tries  to  fix  a 
price  that  will  guard  against  loss,  although  many  of  them  sell 
their  fertilizers  at  times  with  very  small  and  sometimes  no  profit 
when  they  have  a  large  stock  which  they  do  not  wish  to  carry  over 
for  another  season. 

Fertilizer  Laws. — In  order  to  protect  the  consumer  and  the 
honest  manufacturer,  several  states  have  passed  laws  regulating 


Il6  FERTILITY  AND  FERTILIZER   HINTS 

the  sale  of  fertilizers.  The  enforcement  of  these  laws  is  general- 
ly controlled  by  the  Experiment  Stations  or  the  State  Boards  of 
Agriculture,  through  a  staff  of  chemists  and  inspectors.  The 
inspectors,  who  may  or  may  not  be  chemists,  draw  samples  of 
the  various  fertilizers,  forward  them  to  the  laboratory,  and  the 
chemist  analyzes  them  to  find  out  if  they  are  as  represented. 
The  results  of  the  chemists'  findings  .are  published  in  bulletins 
or  reports  which  are  sent  to  the  consumers,  manufacturers,  deal- 
ers, and  other  interested  parties.* 

The  Meaning  of  the  Guarantee.— It  has  been  said  that  the  manu- 
facturer, dealer,  or  jobber  must  have  printed  on  the  bags  or  tags 
attached  to  the  bags,  his  name  and  address,  the  weight  of  the 
package,  the  name,  brand  or  trade  mark,  and  the  chemical  com- 
position of  the  fertilizer.  This  guarantee  does  not  mean  that 
each  particular  shipment,  or  lot,  or  bag,  that  the  consumer  may 
purchase  has  been  analyzed  by  the  state  chemist  and  that  he 
found  the  stipulated  amounts  of  nitrogen,  soluble  phosphoric 
acid,  reverted  phosphoric  acid  and  potash,  as  the  case  may  be, 
that  are  printed  as  the  guaranteed  chemical  analysis  on  the  bags 
or  tags.  It  does  mean  that  the  manufacturer  says  he  has  fur- 
nished at  least  those  amounts  of  plant  food  as  stated. 

The  Interpretation  of  the  Guarantee. — Some  manufacturers  do 
not  make  a  simple  statement  of  the  guaranteed  chemical  com- 
position of  their  brands  of  fertilizers,  but  use  other  terms  which 
are  equivalent,  to  be  sure,  but  are  misleading  to  the  ordinary 
person  not  familiar  with  fertilizer  parlance.  A  few  examples 
may  serve  to  illustrate  this  point. 

Guaranteed  Chemical  Analysis,  No.  i. 

Per  cent. 

Nitrogen i.oo 

Ammonia 1.22 

Equal  to  nitrate  of  soda 6.06 

Total  phosphoric  acid 1 2.00 

Equivalent  to  bone  phosphate 26.00 

Available  phosphoric  acid 10.00 

To  simplify  this  guarantee  we  would  state  it  as : 


COMMKRCIAL  FERTILIZERS  II7 

Per  cent. 

Nitrogen  as  nitrate    i  .00 

Total  phosphoric  acid 1 2.00 

Available  phosphoric  acid 10.00 

All  the  other  statements  omitted  in  the  simplified  chemical 
guarantee  are  correct  btit  unnecessary  and  misleading.  The  per- 
centage given  under  "equal  to  nitrate  of  soda,"  and  "equivalent 
to  bone  phosphate"  are  simply  restatements."" 

Guaranteed  Chemical  Analysis,  No.  2. 

Per  cent. 

Total  phosphoric  acid 1 1-14 

Equivalent  to  total  bone  phosphate 24-30 

Available  phosphoric  acid 10-12 

Equivalent  to  available  bone  phosphate 22-26 

Soluble  phosphoric  acid 8-10 

Equivalent  to  soluble  bone  phosphate 17.5-22 

Insoluble  phosphoric  acid 1-2 

Equivalent  to  insoluble  bone  phosphate 2-4. 25 

Potash 4-5 

Equivalent  to  sulphate  of  potash 7-4-9 

Total  nitrogen 2-3 

Equivalent  to  total  ammonia 2.4-3.6 

This  is  not  an   exaggerated  guarantee  but  one  that  is  often 
found  in  the  fertilizer  trade. 
Simplified  the  above  reads : 

Per  cent. 

Total  phosphoric  acid 11 .00 

Available  phosphoric  acid 10.00 

Soluble  phosphoric  acid   8.00 

Insoluble  phosphoric  acid i.oo 

Potash 4.00 

Nitrogen 2 .00 

Or  we  may  further  simplify  this  to  read ; 

I'er  cent. 

Available  phosphoric  acid 10.00 

Potash 4. 00 

Nitrogen 2.00 

It  will  be  noticed  that  the  simplified  statements  contain  the 
minimum  percentages ;  for  example,  available  phosphoric  acid  is 
guaranteed  as  10  to  12  per  cent,  and  in  the  simplified  statement 
it  is  given  as  being  10  per  cent.     This  latter  figure  10  per  cent. 


115  FERTILITY    AND   FERTILIZER    HINTS 

is  all  the  manufacturer  guarantees  and  the  maximum  guarantee 
of  12  per  cent,  is  misleading  and  does  not  mean  anything.  It 
seems  to  be  common  practice  with  the  manufacturers  to  use  both 
the  minimum  and  maximum  guarantees. 

Guaranteed  Chemical  Analysis.  No.  3. 

Per  cent. 

Total  phosphoric  acid 10-12 

Available  phosphoric  acid 9-10 

Insoluble  phosphoric  acid 1-2 

Soluble  phosphoric  acid 6-8 

Equal  to  available  bone  phosphate 19.7-22 

Potash 3.5-5 

Nitrogen  . .    0.82-1.65 

Ammonia 1-2 

Simplified  this  guarantee  would  read : 

Per  cent. 

Available  phosphoric  acid 9.00 

Potash 3.5 

Nitrogen 0.82 

Guaranteed  Chemical  Analysls,  No.  4. 

Per  cent. 

Total  bone  phosphate 32.7-43.7 

Yielding  total  phosphoric  acid 15-20 

Soluble  bone  phosphate 22-28 

Yielding  soluble  phosphoric  acid 10-13 

Reverted  bone  phosphate 8.7-10.9 

Yielding  reverted  phosphoric  acid 4-5 

Insoluble  bone  phosphate 2. 2-4.4 

Yielding  insoluble  phosphoric  acid 1-2 

Simplified  this  would  read : 

Soluble  phosphoric  acid 10.00 

Reverted  phosphoric  acid 4.00 

Insoluble  pho.sphoric  acid i .00 

Or  we  could  state  it  as  follows: 

Available  phosphoric  acid  14.00 

There  are  many  manufacturers  who  put  guarantees  on  their 
brands  that  are  not  misleading  and  may  be  easily  interpreted 
by  the  ordinary  person.* 


CHAPTER  XIII. 


VALUATION  OF  FERTILIZERS. 

Interpretation  of  Chemical  Analyses. — -\  chemical  analysis  of  a 
fertilizer  may  indicate  to  a  great  extent  the  value  or  suitability 
of  it.     The  following  two  analyses  illustrate   this   point. 
Chemical  Analysis,  No.  i. 

Per  cent. 

Nitrogen  as  nitrate i  .00 

Nitrogen  as  ammonia i .  00 

Organic  nitrogen 2.00 

Total  nitrogen 4.00 

Water  soluble  phosphoric  acid 8.00 

Reverted  phosphoric  acid 2.00 

Insoluble  phosphoric  acid 2.00 

Available  phosphoric  acid 10.00 

Total  potash 9.00 

Potash  as  chloride 2.00 

Potash  as  sulphate 7.00 

Chemical  Analysis,  No.  2. 

Per  cent. 

Nitrogen  as  nitrate 

Nitrogen  as  ammonia 

Organic  nitrogen 4.00 

Total  nitrogen 4.00 

Water  soluble  phosphonc  acid 2.00 

Reverted  phosphoric  acid 8.00 

Insoluble  phosphoric  acid 2.00 

Available  phosphoric  acid 10.00 

Total  potash 9.00 

Potash  as  chloride 8.00 

Potash  as  sulphate i .00 

Both  of  the  above  fertilizers  contain  equal  amounts  of  nitrogen, 
phosphoric    acid    and    potash    and    could    be    stated    as    follows: 

Per  cent. 

Nitrogen 4.00 

Available  phosphoric  acid 10.00 

Potash  9.00 

Fertilizer  No.  i  contains  nitrogen  as  nitrates  and  as  ammonia 
while  Xo.  2  does  not.     Both  brands  contain  organic  nitrogen ; 
9 


120  FERTILITY   AND  FERTILIZER    HINTS 

No.  I  containing  2  per  cent,  and  No.  2  carries  all  of  its  nitrogen 
in  this  form.  The  chemist  cannot  always  tell  the  source  of  the 
organic  nitrogen.  When  the  organic  nitrogen  is  derived  from 
dried  blood,  azotin,  cotton-seed  meal,  steamed  horn  and  hoof 
meal,  and  similar  nitrogenous  organic  materials  it  is  valuable  but 
when  derived  from  leather  preparations,  dissolved  wool  and 
shoddy  wastes,  etc.,  it  is  not  so  desirable.  Therefore  the  pur- 
chaser would  perhaps  select  Brand  No.  i  for  its  nitrogen  con- 
tent as  it  is  to  be  supposed  that  the  manufacturer  using  high 
grade  materials  as  nitrate  of  soda  and  sulphate  of  ammonia  would 
furnish  organic  nitrogen  from  high  grade  materials. 

A  glance  at  the  phosphoric  acid  constituents  shows  that  both 
run  10  per  cent,  available  phosphoric  acid  but  No.  i  contains  6 
per  cent,  more  phosphoric  acid  in  the  soluble  form.  As  soluble 
phosphoric  acid  distributes  more  readily  in  the  soil  than  reverted 
phosphoric  acid  and  is  more  available  as  plant  food,  we  would 
naturally  prefer  Analysis  No.  i  from  the  phosphoric  acid  stand- 
point. Glancing  at  the  potash  we  find  that  No.  i  carries  2  per 
cent,  as  chloride  and  7  per  cent,  as  sulphate,  while  No.  2  shows 
8  per  cent,  as  chloride  and  i  per  cent,  as  sulphate.  For  crops 
like  tobacco,  potatoes,  sugar-beets,  oranges,  etc..  No.  i  would 
be  the  most  suitable,  since  these  crops  do  better  with  sulphate  of 
potash  than  with  muriate  of  potash.  The  potash  in  No.  i  was  in 
all  probability  derived  mostly  from  sulphate  of  potash  while  that 
in  No.  2  came  mostly  from  muriate  of  potash. 

Here  is  another  statement  that  is  used  by  some  chemists  in  re- 
porting analyses. 

Chemical  Analysis,  No.  3. 

rer  cent. 

Nitrogen 3.00 

Soluble  phosphoric  acid 7.00 

Reverted  phosphoric  acid 3.00 

Insoluble  phosphoric  acid 2.00 

Available  phosphoric  acid 1 0.00 

Potash 9.00 

This  Statement  is  not  so  valuable  as  Nos.  i  and  2  because  the 
forms  of  nitrogen  and  potash  are  not  given.  The  nitrogen  may 
all  be  from  nitrate  of  soda,  or  sulphate  of  ammonia,  or  organic 


VALUATION    OF    FERTILIZERS  121 

sources,  or  from  any  two  or  perhaps  be  furnished  from  all  of 
these  sources.  The  potash  may  be  as  sulphate,  or  as  chloride, 
or  as  carbonate,  or  as  a  mixture  of  any  two  or  three  of  these 
forms  in  any  proportion. 

Here  is  still  another  statement. 

Chemical  An.\lysis,  No.  4. 

Per  cent. 

Nitrogen 4.00 

Available  phosphoric  acid 10.00 

Potash 9.00 

This  analysis  besides  not  furnishing  the  amounts  of  the  forms 
of  nitrogen  and  potash  does  not  give  the  forms  of  phosphoric 
acid.  Of  this  10  per  cent,  available  phosphoric  acid  all  of  it 
may  be  as  soluble,  or  as  reverted.  It  may  contain  both  soluble 
and  reverted  phosphoric  acid  but  in  just  what  amounts  we  do 
not  know. 

The  chemical  analysis,  when  the  different  forms  of  plant  food 
are  reported,  may  often  prove  of  value  to  those  farmers  who  can 
interpret  them  and  who  understand  the  influence  of  the  plant  food 
forms  on  profitable  crop  production. 

Agricultural  Values. — The  agricultural  value  of  a  fertilizer 
is  represented  by  the  crop  produced.  The  price  that  is  paid  for 
a  fertilizer  has  no  bearing  on  its  agricultural  value.  The  agri- 
cultural value  will  vary  with  the  season,  the  amount  of  fertilizer 
used,  the  nature  of  the  soil,  kind  of  crop,  care  of  the  crop,  locality, 
insect  damage,  plant  diseases,  and  many  other  conditions.  It 
cannot  be  estimated  and  is  often  beyond  the  control  of  man. 
However,  the  nature  of  the  materials  that  make  up  a  fertilizer 
may  influence  its  agricultural  value.  Market  garden  crops  will 
no  doubt  do  better  with  fertilizers  containing  plant  food  in 
available  and  soluble  forms.  For  example,  available  phosphoric 
acid  will  give  quicker  returns  than  insoluble  phosphoric  acid. 
Nitrogen  in  a  soluble  form  will  be  taken  up  more  readily  than 
nitrogen  in  an  organic  form  and  some  organic  forms  of  nitrogen 
will  be  more  quickly  available  than  others.  In  other  words 
fertilizers  that  give  up  their  i)lant  food  slowly  will  not  have  a 
high  agricultural  value  for  ([uick  growing  crops. 


122  FERTILITY   AND  FERTILIZER   HINTS 

Again,  the  crop  to  be  raised  may  have  a  long  growing  season. 
If  such  is  the  case  it  would  not  pay  to  use  fertilizer  whose  plant 
food  is  all  in  soluble  forms.  If  the  nitrogen  is  all  soluble,  as  in 
nitrate  of  soda  and  sulphate  of  ammonia,  it  may  be  used  up  or 
lost  before  the  crop  has  finished  growing  and  some  slower  acting 
form  of  nitrogen,  as  is  contained  in  dried  blood,  cotton-seed 
meal,  tankage,  etc.,  would  no  doubt  give  greater  crop  returns. 

The  value  of  the  crop  must  also  be  considered,  for  crops  of 
low  market  value  cannot  be  expected  to  give  profitable  returns 
with  high  priced  fertilizers.  The  cost  of  a  fertilizer  of  low 
agricultural  value  may  be  greater  than  one  that  has  a  high  value 
in  producing  crops.  Farm  manures,  wood  ashes,  land  plaster, 
etc.,  may  be  comparatively  high  in  price  for  the  amount  of  plant 
food  they  contain  or  the  good  they  do. 

Commercial  Values. — The  commercial  value  of  a  fertilizer  is 
entirely  different  from  the  agricultural  value.  It  represents 
the  retail  cost  of  raw  materials  of  standard  quality  in  the  market, 
from  which  the  commercial  or  trade  value  of  plant  food  may  be 
calculated.  For  example,  nitrate  of  soda  may  be  quoted  at  $50 
a  ton.  This  represents  its  commercial  value.  As  nitrate  of  soda 
contains  15.5  per  cent,  of  nitrogen  or  310  pounds  of  nitrogen  in 
a  ton,  its  nitrogen  has  a  commercial  or  trade  value  of  a  little 
over  16  cents  a  pound.  An  acid  phosphate  containing  14  per 
cent,  of  available  phosphoric  acid  may  carry  a  retail  price  of  $14 
a  ton,  which  is  its  commercial  value.  The  commercial  or  trade 
value  of  the  available  phosphoric  acid  would  be  5  cents  a  pound, 
since  14  per  cent,  of  available  phosphoric  acid  is  equal  to  280 
pounds  of  available  phosphoric  acid  in  a  ton.  Or  an  acid  phos- 
phate may  be  quoted  at  $1  per  unit.  This  is  its  commercial  value. 
This  means  that  the  retail  cost  of  20  pounds  of  available  phos- 
phoric acid  is  $1.  The  commercial  or  trade  value  is  then  5  cents, 
a  pound.  The  commercial  or  trade  value  does  not  mean  that 
nitrogen  at  16  cents  a  pound  will  produce  16  cents  worth  of 
crops,  or  available  phosphoric  acid  at  5  cents  a  pound  will  pro- 
duce crops  that  will  bring  5  cents.  These  constituents  may  pro- 
duce crops  valued  at  more  or  less  than  16  and  5  cents  respectively, 
depending  upon  many  conditions  as  season,  locality,  kind  or  crop, 


VAI^UATION    OF    FHRTILIZIiRS  1 23 

condition  of  the  soil,  tillage,  etc.  The  commercial  or  trade  value 
only  serves  as  a  comparison  of  the  relative  values  of  the  different 
forms  of  plant  food  in  the  raw  materials.  This  valuation  does 
not  represent  the  cost  of  the  mixed  goods.  In  the  manufacture 
of  fertilizers  the  cost  of  mixing,  sacking,  dryers,  manufacturers' 
profit,  long  credits,  freight,  insurance,  agents'  profits,  etc.  are 
all  added  to  this  commercial  or  trade  value,  so  that  the  farmer 
pays  much  more  for  plant  food  than  is  represented  in  the  com- 
mercial or  trade  valuation.  But  the  farmer  may  purchase  the 
plant  food  contained  in  the  raw  materials  (unmixed),  for  the 
prices  as  represented  by  the  commercial  or  trade  values,  at  those 
points  where  the  retail  prices  are  quoted.  To  get  the  fertilizer 
to  his  farm  he  will  of  course  have  to  pay  freight. 

Trade  Values. — The  Experiment  Stations  of  Connecticut,  New 
York,  Rhode  Island,  Massachusetts.  New  Jersey  and  Vermont 
make  out  trade  values  every  year  for  those  materials  that  are 
most  commonly  used  in  the  manufacture  of  mixed  fertilizers. 
These  values  are  arrived  at  by  calculating  the  prices  of  fertilizer 
materials  for  the  six  months  preceding  March  ist.  and  are  ob- 
tained from  the  leading  markets  of  southern  New  England  and 
the  middle  northern  states. 

Trade  Values  of  Fertilizing  Ingredients  in  Raw  Materials 
AND  Chemicals  for  1909.' 

Cts.  per  lb. 

Nitrogen  in  nitrates j6}4 

Nitrogen  in  ammonia  salts 17 

Organic  nitrogen  in  dry  and  fine  ground  fish,  blood  and 

meat  and  in  mixed  fertilizers 19 

Organic  nitrogen  in  fine  ground  bone  and  tankage 19 

Organic  nitrogen  in  coarse  bone  and  tankage 14 

Phosphoric  acid  soluble  in  water 4 

Phosphoric  acid  soluble  in  ammonium  citrate 31^ 

Phosphoric  acid  in  fine  ground  bone  and  tankage 3'^ 

Phosphoric  acid  in  coarse  bone  and  tankage 3 

Phosphoric  acid  insoluble  (in  water  and  in  ammonium 

citrate)  in  mixed  fertilizers 2 

Potash  as  high  grade  sulphate  and   in  mixtures   free 

from  muriate  f  chloride) 5 

Potash  as  muriate 4^ 

Vermont  Experiment  Station. 


124  FERTILITY   AND  FERTILIZER   HINTS 

How  Obtained. — To  give  an  idea  of  how  these  trade  values  are 
obtained  we  may  presume  that  the  wholesale  price  of  sulphate 
of  ammonia  for  the  six  months  preceding  March  ist  averaged 
$56.80  per  ton,  or  14.2  cents  a  pound  for  the  nitrogen.  A  cer- 
tain amount,  usually  20  per  cent,  is  added  to  this  wholesale  price 
to  cover  the  cost  of  handling,  insurance,  etc.,  which  would  raise 
the  price  to  $68  i^er  ton,  which  would  be  the  retail  or  commercial 
value  of  ammonium  sulphate.  The  nitrogen  then  would  be 
represented  as  carrying  a  commercial  or  trade  value  of  17  cents 
a  pound.  The  trade  values  on  all  other  fertilizer  materials  are 
calculated  in  the  same  way  as  described  for  sulphate  of  ammonia. 

A  Discussion  of  the  Table  of  Trade  Values. — A  study  of  the 
table  is  interesting.  It  shows  that  valuations  are  given  for 
nitrogen  as  nitrate,  as  ammonia  and  as  organic  nitrogen.  The 
trade  values  for  organic  nitrogen  are  also  different  depending 
upon  the  source.  Soluble  phosphoric  acid  is  valued  higher  than 
reverted  phosphoric  acid  and  there  is  also  a  trade  value  for  in- 
soluble phosphoric  acid.  In  some  states  there  is  no  distinction 
made  between  soluble  and  reverted  phosphoric  acid  in  trade 
valuation  and  the  insoluble  phosphoric  is  often  not  considered  at 
all.  The  bone  products  in  the  foregoing  table  are  valued  on  their 
degree  of  fineness ;  the  finer  bone-meals  command  higher  market 
prices  than  those  that  are  coarse  as  is  shown  in  the  trade  valua- 
tions of  nitrogen  and  phosphoric  acid.  The  potash  as  sulphate 
carries  a  higher  trade  value  than  potash  as  chloride,  but  this  is 
to  be  expected  because  sulphate  of  potash  costs  more  to  manu- 
facture than  muriate  of  potash.  There  are  many  fertilizer 
materials  not  included  in  the  above  table.  Those  included  in 
the  table  are  high  class  products  commonly  used  in  New  England 
and  New  Jersey. 

How  to  Calculate  the  Commercial  Value  of  a  Fertilizer. — Let  us 
suppose  a  chemist  analyzes  a  mixed  fertilizer  and  finds  its  com- 
position to  be  as  follows : 


VALUATION    OF    l-RRTILIZEKS  I25 

Chemical  Analysis. 

Per  cent. 

Nitrogen  as  nitrates 0.50 

Nitrogen  as  ammonia i .30 

Nitrogen  as  organic 2.00 

Water  soluble  phosphoric  acid 6.00 

Phosphoric  acid  soluble  in  aniraonium  citrate  (reverted)   1.80 
Phosphoric   acid   insoluble   (in   water   and   ammonium 

citrate) i  .50 

Potash  as  sulphate 0.40 

Potash  as  chloride 3.60 

The  commercial  valuation  of  the  above  fertilizer  would  be  ob- 
tained by  multiplying  each  ingredient  by  20  to  change  to  a  ton 
basis,  and  multiplying  this  product  by  the  trade  value  of  each. 
The  sum  of  these  values  would  be  the  total  commercial  value  as 
derived  from  the  raw  products. 

Commercial  Valuation. 

Pounds                              Trade  Coninier- 

per  100             Pound.s    value  cial  value 

or  per.                 per       per  lb.  per 

cent.                  ton       cents  ton 

Nitrate  nitrogen 0.50X20=     10  X  16.5  =  f  r.65 

Ammonia  nitrogen 1.30X20=    26X17  =    4-42 

Organic  nitrogen 2.00  X  20  ^    40  X  19  =    7-6o 

Soluble  phosphoric  acid 6.00  X  20  =  120  X    4  =    4.80 

Reverted  phosphoric  acid 1.80X20^    36  X    3-5  =    1.26 

Insoluble  phosphoric  acid 1.50  X  20  :=    30  X    2  =    0.60 

Potash  as  sulphate 0.40  X  20  =      8X5  =^    o-4o 

Potash  as  chloride 3.60X20=    72  X    4.25=    3.06 

Total  commercial  value* —  $23.79 


CHAPTER  XIV. 


HOME  MIXTURES. 

Definitions. — When  fertilizer  materials  such  as  tankage,  dried 
blood,  nitrate  of  soda,  sulphate  of  ammonia,  superphosphate,  bone 
meal,  muriate  of  potash,  etc.,  are  purchased  and  mixed  at  home 
the  process  is  called  home  mixing  and  the  product  a  home  mix- 
ture. When  these  fertilizer  materials  are  mixed  by  the  factory 
the  product  is  called  a  fertilizer  or  a  mixed  fertilizer.  Most  of 
the  fertilizer  materials  contain  either  one  or  two  constituents  and 
only  a  few  carry,  all  three  constituents.  Most  of  the  mixed 
fertilizers  contain  three  constituents,  namely,  nitrogen,  phosphoric 
acid  and  potash  and  are  called  complete  fertilizers  because  they 
contain  the  three  essential  elements.  There  has  been  a  great 
deal  of  discussion  as  to  whether  fertilizer  materials  or  mixed 
fertilizers  are  the  best  for  the  consumer  to  purchase. 

Manufacturer's  Claims. — The  manufacturers  claim  that  mixed 
fertilizers  are  the  best  for  the  farmer  to  purchase  because : 

1.  The  factory  mixed  fertilizers  are  in  a  fine  mechanical  con- 
dition. The  mixed  fertilizers  are  ground  fine  and  uniformly 
mixed,  which  is  indeed  an  important  consideration  to  permit  of 
an  even  distribution  on  the  land. 

2.  The  mixed  fertilizers  can  generally  be  purchased  in  the 
locality  at  most  any  time  and  in  any  amount. 

3.  The  mixed  fertilizers  are  specially  treated  with  acid  and  the 
constituents  in  substances  like  tankage,  dry  ground  fish,  etc.,  are 
made  partially  available. 

4.  The  mixed  fertilizers  are  claimed  to  be  made  up  in  such 
proportions  as  to  satisfy  the  needs  of  crops. 

5.  The  manufacturers  often  allow  the  farmer  some  time  to 
settle  and  often  wait  until  harvest  time  before  getting  their 
money.  The  credit  system  is  in  vogue  in  the  South  where 
enormous  quantities  of  mixed  fertilizers  are  used. 

Reasons  Why  the  Farmer  Should  Mix  Fertilizer  Materials  at 
Home. — The  mixing  of  fertilizer  materials  at  home  is  becoming 


IIOMli:     MIXTURES  127 

more  popular  among-  the  farmers.  Some  of  the  reasons  why  the 
farmer  should  mix  his  own  fertilizer  materials  follow : 

1.  Plant  food  is  obtained  at  a  lower  price. 

2.  The  farmer  knows  the  materials  used. 

3.  L^nnecessary  constituents  arc  not  purchased. 
Mechanical  Condition  of  Factory  and  Home  Mixed  Fertilizers. — 

The  factory  mixed  fertilizers  are  usually  much  better  mixed  than 
those  that  are  mixed  at  home.  Fertilizer  factories  are  well 
equipped  with  special  machinery  to  insure  producing  a  uni- 
form product  that  may  easily  be  distributed  on  the  farm.  How- 
ever, the  careful  farmer  may  mix  his  fertilizer  materials  uniformly 
enough  for  all  practical  purposes. 

Mixed  Fertilizers  More  Easily  Purchased. — Mixed  fertilizers 
can  generally  be  purchased  in  the  locality  and  the  raw  materials 
must  be  ordered  away  from  home  which  of  course  takes  some 
time.  Sometimes  certain  raw  materials  are  hard  to  obtain.  If 
the  farmer  starts  early  enough,  say  in  the  winter,  the  raw 
materials   can   generally  be   obtained. 

Mixed  Fertilizers  Compounded  for  the  Needs  of  the  Crop. — When 
a  manufacturer  makes  up  his  formulas  he  has  to  allow  for  the 
general  existing  conditions  of  soil,  climate,  and  needs  of  the 
crop,  and  he  cannot  expect  to  make  a  particular  brand  that  will 
suit  each  farmer's  requirements.  When  he  makes  up  a  potato 
brand  he  must  make  a  mixture  that  will  suit  most  of  the  farmers 
growing  potatoes  and  he  cannot  expect  to  meet  every  condition 
of  soil. 

Manufacturers  Often  Allow  Credit. — On  the  whole,  the  credit 
system  is  a  poor  system  for  the  farmer,  for  when  his  crop  is 
made  he  may  or  may  not  be  ahead  financially.  Those  that  live  on 
the  credit  system  are  usually  a  year  behind  and  two  or  three 
poor  crops  results  in  the  loss  of  the  farm.  The  manufacturers, 
however,  are  often  too  lenient  in  selling  their  mixed  fertilizers 
on  the  credit  basis  as  they  often  have  large  losses  which  take 
away  much  of  their  profit. 

Plant  Food  is  Obtained  at  a  Lower  Price  in  Home  Mixtures, — 
The  work  of  the   Experiment   Stations  has  j)roved  conclusively 


128  FERTILITY  AND  FERTILIZER  HINTS 

that  plant  food  is  obtained  at  a  lower  price  when  the  fertilizer 
materials  are  purchased  and  mixed  at  home  than  when  mixed 
fertilizers  are  employed.  Of  course  in  using  home  mixtures, 
freight  on   fillers   is   saved.* 

Home  Mixing  Acquaints  the  Farmer  with  the  Materials  Used. — 

When  a  farmer  buys  a  factory  mixed  fertilizer  he  does  not  always 
know  just  the  sources  of  the  nitrogen,  phosphoric  acid  and  potash. 
He  may  desire  his  potash  wholly  as  sulphate ;  he  may  want  a  part 
of  his  nitrogen  as  nitrate  and  a  part  in  the  organic  form  from 
dried  blood.  When  he  buys  factory  mixed  fertilizers  he  has  to 
take  the  word  of  the  agent  or  the  manufacturer.  Most  manu- 
facturers are  honest  men  who  give  what  is  asked  for  but  when 
you  mix  at  home  you  know  just  the  amount  and  kind  of  materials 
you  are  using.  Again,  when  you  mix  your  own  fertilizer 
materials  you  deal  in  the  subject  "plant  food,"  that  is,  so  much 
nitrogen,  so  much  available  phosphoric  acid  and  so  much  potash, 
and  you  do  away  with  your  old  bad  habit  of  purchasing  fertilizer 
for  a  given  amount  per  ton  regardless  of  its  plant  food  value. 

Home  Mixing  Does  Away  with  the  Purchase  of  Unnecessary 
Constituents. — Manufacturers  make  many  brands  of  fertilizers 
but  as  previously  said  they  cannot  make  one  brand  that  will  suit 
the  requirements  of  every  individual  farmer.  For  example,  two 
farmers  in  the  same  locality  wish  to  purchase  a  mixed  fertilizer 
for  their  corn.  One  of  these  farmers  may  have  applied  farm 
manure  or  he  may  have  plowed  under  a  leguminous  crop,  while 
the  other  farmer  has  not  supplied  his  soil  with  any  organic  matter 
and  his  soil  may  be  poor  and  in  need  of  humus.  The  fertilizer 
agent  or  merchant  in  this  particular  locality  is  selling  a  corn 
fertilizer  guaranteed  to  contain  nitrogen,  phosphoric  acid  and 
potash  in  stipulated  amounts.  Is  it  reasonable  to  suppose  that 
this  one  brand  of  corn  fertilizer  is  the  best  fertilizer  for  both  soils 
under  the  above  conditions?  The  first  farmer  who  has  supplied 
farm  manure  or  plowed  under  a  leguminous  crop  would  be 
wasting  money  in  purchasing  nitrogen,  unless  a  little  in  the 
form  of  nitrate,  which  may  help  to  give  the  crop  a  start.  The 
other  farmer  would  need  a  fertilizer  containing  both  nitrogen  as 


HOINIK     MIXTUKI 


l.HJ 


nitrate  and  nitrogen  in  some  desirable  organic  form  to  help  pro- 
duce a  crop.  Again,  a  farmer  may  be  growing  cotton,  corn, 
sugar-cane,  etc.,  on  a  soil  that  is  very  rich  in  available  potash. 


Fig.  II.— Corn  is  a  crop  that  thrives  on  farm  manure. 


It  would  certainly  be  a  waste  of  money  for  him  to  purchase  a 
fertilizer  containing  potash. 


130  FERTILITY  AND  FKRTILIZER  HINTS 

When  home  mixing  is  practiced  the  farmer  can  purchase  those 
fertihzer  materials  that  supply  the  needed  constituents  and  in  the 
most  desirable  forms  for  the  needs  of  his  soil  and  crop. 

How  to  Purchase  Fertilizer  Materials — The  large  consumer 
should  certainly  try  home  mixing  and  lind  out  its  advantages. 
The  small  farmer  may  find  it  impracticable  to  purchase  other 
than  factory  mixed  fertilizers.  However,  several  small  consum- 
ers may  often  advantageously  club  together  and  purchase 
fertilizer  materials  in  mixed  carload  lots.  Many  manufacturers 
will  gladly  mix  fertilizer  materials  for  the  farmer  when  the  order 
is  large  enough.  Of  course  the  farmer  must  know  just  the 
amounts  and  kinds  of  materials  he  wishes  wdien  he  orders  in  this 
way. 

To  purchase  fertilizer  materials  to  mix  at  home,  it  is  necessary 
to  start  early,  say  in  the  early  winter,  so  that  they  may  be  mixed 
before  the  heavy  spring  work  starts.  Quotations  should  be 
secured  from  different  parties  in  the  nearest  or  nearby  fertilizer 
markets.  In  most  large  cities  bids  can  be  secured.  Re  ready 
to  pay  cash  because  these  raw  materials  are  not  usually  sold  on 
credit.  Buy  on  the  guarantee  and  if  the  constituents,  nitrogen, 
phosphoric  acid  and  potash  fail  to  reach  their  guarantees  de- 
mand a  rebate.  This  can  be  easily  arranged  by  making  a  con- 
tract with  the  manufacturer  or  broker. 

How  to  Mix  Fertilizer  Materials  at  Home. — The  fertilizer  ma- 
terials may  be  mixed  in  a  wagon  box,  or  better,  on  a  tight  barn 
floor,  or  a  floor  covered  with  canvas.  Whenever  chemicals  as 
nitrate  of  soda,  potash  salts,  etc.  are  used,  they  should  be  well 
broken  up  and  rendered  as  fine  as  possible.  In  mixing,  the  light 
bulky  materials  as  dried  blood,  cotton-seed  meal,  dry  ground  fish, 
etc.,  should  be  put  on  the  bottom  of  the  floor  and  on  top  of  these 
spread  the  other  materials.  The  materials  should  be  spread  even- 
ly and  then  turned  over  and  over  and  thoroughly  mixed  by  shovel- 
ling. It  takes  considerable  time  to  mix  fertilizer  materials  so 
that  the  mixture  is  uniform.  After  the  mixing  is  completed  the 
fertilizers  should  be  bagged  and  kept  in  dry  storage  until  ready 
for  use.     If  the  mixture  predominates  in  concentrated  salts,  some 


HOMIC     MIXTURKS  I3I 

oartli  nia\  be  incorporated  to  insure  a  more  even  mixture.  It 
should  be  remembered  that  the  chief  advantage  of  buying  factory 
mixed  fertiUzers  is  that  they  are  better  mixed  and  the  farmer 
cannot  spend  too  much  time  in  the  process  of  thoroughly  mixing 
his  fertilizer  materials.* 

How  to  Calculate  Percentages  from  Known  Amounts. — Suppose 
you  want  to  find  out  the  analysis  of  a  mixture  made  up  of  the 
following : 

Mixture. 
600  lbs.  acid  phosphate  analj'zing  14  %  available  phosphoric  acid 
150  lbs.  sulphate  of  ammonia  analyzing  20  ''/c  nitrogen 
100  lbs.  sulphate  of  potash  analyzing  50  %  potash. 

850  lbs.  Total. 

To  find  out  the  number  of  pounds  of  available  phosphoric  acid, 
nitrogen  and  potash  in  the  above  mixture,  make  the  following 
multiplication. 

6     X  14  =  84  lbs.  available  phosphoric  acid 
1.5  X  20  =  30  lbs.  nitrogen 
I      X  50  =  50  lbs.  potash, 

To  calculate  the  percentages  of  available  phosphoric  acid, 
nitrogen  and  potash,  divide  the  amounts  of  the  constituents  by 
the  total  amount  of  the  mixture. 

Available  phosphoric  acid,  lbs.  84  -f-  850  ^  9.88  %  available  phosphoric  acid 

Nitrogen lbs.  30  -i-  850  =  3.53  Jo  nitrogen 

Potash lbs.  50  -i-  850  =  5.88  fo  potash. 

If  percentages  are  wished  when  one  of  the  materials  contains 
two  constituents,  the  calculations  may  be  made  as  follows : 
Mixture. 

200  lbs.  dissolved  bone  analyzing    \    '^        J  available  phosphoric  acid 

-'       °    (      2.5     ^  nitrogen 
100  lbs.  nitrate  of  soda  analyzing  18.84  %  ammonia 

50  lbs.  carbonate  of  potash  analyzing  64.00  %  potash. 

350  lbs.  Total. 

The  dissolved  bone  superphosphate  furnishes  two  constituents, 
available  phosphoric  acid  and  nitrogen,  so  we  must  take  these 
into  consideration  in  our  calculations. 


132  FERTIUTY  AND  rERTILIZEK    HINTS 

The  nitrate  of  soda  is  given  as  carrying  an  equivalent  of  18.84 
per  cent,  of  ammonia.  To  convert  ammonia  into  nitrogen  we 
must  multiply  by  the  factor  0.823. 

18,84  Jo  ammonia  X  0.823  =  15.5   %  nitrogen. 

Then  : 

2      X  15      =  30  o  lbs.  available  phosphoric  acid 

2      X    2.5  =    5.0  lbs.  nitrogen  from  dissolved  bone  superphosphates 

1      X  15-5  =  15-5  lbs.  nitrogen  from  nitrate  of  soda 

0.5  X  64     =  32.0  lbs.  potash. 

The  percentages  in  this  mixture  would  be : 
Available  phosphoric  acid  lbs.  30     -^  350  =  8.57  Jr  available  phosphoric  acid 

Nitrogen lbs.  20.5  -j-  350  =  5.85  Jo  nitrogen 

Potash lbs.  32    H-  350  =  9. 14  Jc  potash. 

How  to  Calculate  Amounts  from  Known  Percentages. — If  2.000 
pounds  of  a  mixture  analyzing 

Available  phosphoric  acid  7  per  cent. 

Nitrogen 5  per  cent. ,  and 

Potash 6  per  cent. 

is  desired  from 

Acid  phosphate  analyzing  16  Jo  available  phosphoric  acid. 
Calcium  cyanamid    "  17  Jo  nitrogen,  and 

Muriate  of  potash     "  50  ^ir  potash. 

it  may  be  calculated  in  the  following  way : 

First  find  out  the  number  "of  pounds  of  available  phosphoric 
acid,  nitrogen  and  potash  that  would  be  required.     Since  2,000 
IS  20  times  100  we  may  multiply  the  percentages  by  20. 
20  X  7  (  ^  avail,  phos.  acid)  =  140 lbs.  avail,  phos.  acid  required  for  2,000 lbs. 
20  X  5  (%  nitrogen )  =  loolbs.  nitrogen  "  "       "       " 

20X6  (%  potash)  —  1 20 lbs.  potash 

To  determine  the  number  of  pounds  of  acid  phosphate,  calcium 
cyanamid  and  muriate  of  potash  needed  to  give  the  analysis 
desired,  we  may  divide  the  pounds  of  available  phosphoric 
acid,  nitrogen  and  potash  by  the  percentages  that  the  materials 
analyzed. 
Avail,  phos.  acid  lbs.  140  -r-  16  V  =  S75  lbs.  acid  phosphate  required 
Nitrogen  "     lot^  -i-  17  ^  :=  588  lbs.  calcium  cynamid  required 

Potash  ■■     120-j-  50  Jc  ^=  240  lbs.  muriate  of  potash  required 

Total =  1,703  lbs 


HOME     MIXTURES  133 

We  have  only  1,703  pounds  and  not  2,000  pounds  the  amount 
desired.  To  make  2,000  pounds  an  addition  of  297  pounds  of 
some  make  weight  material  as  sand,  earth,  gypsum,  etc.,  is 
necessary. 

Supposing  we  wished  to  substitute  kainit,  analyzing  12  per 
cent,  of  potash,  for  the  muriate  of  potash  in  the  above  mixture. 
By  calculating  as  explained  above  we  find  that  it  would  require 
1,000  pounds  of  kainit  to  analyze  6  per  cent,  of  potash.  This 
amount  would  make  our  total  add  up  to  2,463  pounds,  or  463 
pounds  more  than  we  wish.  This  shows  that  kainit  could  not  be 
used  to  supply  all  of  the  potash  in  a  2,000  pound  mixture  of  the 
above  analysis  made  from  such  materials.  We  could  however 
supply  one-third  of  the  potash  from  kainit  and  two-thirds  from 
m.uriate  of  potash. 

Potash  lbs.  from  kainit     40  -i-  12  %  -~  333  lbs.  kainit 

Potash  lbs.  from  muriate  80  -i-  50  %  =  160  lbs.  muriate  of  potash. 

Assembling  the  potash  salts,  acid  phosphate  and  calcium  cyan- 
am  id  we  have : 

Pounds 

Acid  phosphate 875 

Calcium  cyanamid 588 

Kainit 333 

Muriate  of  potash 160 

Total 1 ,956 

By  using  kainit  and  muriate  of  potash  in  the  above  proportions 
only  44  pounds  of  filler  would  be  necessary  to  add  to  make  2,000 
pounds.^' 


CHAPTER  XV. 


A  FEW  REMARKS  ABOUT  FERTILIZERS. 

Brand  and  Trade  Names. — There  are  too  many  farmers  who 
purchase  feitihzers  on  the  brand  or  trade  name  and  not  on  the 
plant  food  these  fertihzers  contain.  The  manufacturers  are  well 
acquainted  with  the  importance  of  selling  their  fertilizers  under 
attractive  names.  Some  of  the  manufacturers  even  go  so  far  as 
to  have  their  brand  names  copyrighted  to  prevent  their  com- 
petitors from  using  them.  Some  of  the  older  brand  or  trade 
names  are  well  known  by  all  the  farmers  in  the  locality  vvhere 
they  have  been  sold  from  year  to  year  and  many  of  these  farmers 
purchase  Dixie  Cotton  Fertilizer,  Great  Western  Wheat  Fertili- 
zer, Home  Mixture,  Standard  Special  Tobacco  Manure,  Cele- 
brated Potato  Fertilizer,  Royal  Corn  Special,  etc.,  from  year 
to  year  without  ever  knowing  their  plant  food  content.  The 
name  sounds  good  to  these  farmers,  the  fertilizer  has  a  good 
strong  odor,  the  right  color,  and  with  some  farmers  the  proper 
taste.  These  are  brand  and  ton  farmers  and  not  plant  food 
farmers.  These  farmers  will  tell  you  that  their  fathers  used 
these  same  fertilizers. 

To  show  that  the  name  is  no  indication  of  the  composition  and 
suitableness  of  a  fertilizer  for  a  crop,  the  following  data  is  sub- 
mitted. In  the  state  of  Massachusetts  for  the  year  1909, 
out  of  66  brands  sold  as  potato  fertilizers,  46  contained  potato 
as  the  only  crop  name,  and  20  were  sold  in  conjunction  with  other 
crop  names  as  potato,  hop,  and  tobacco ;  potato  and  root  crop ; 
potato  and  tobacco ;  potato  and  vegetable ;  corn  and  potato ; 
potatoes,  roots  and  vegetables  ;  onion  and  vegetables.  Twelve  com- 
panies put  out  2  brands,  5  put  out  3  brands,  and  3  put  out  4  brands. 
The  nitrogen  guaranteed  varied  from  0.80  to  3.71  per  cent.,  the 
available  phosphoric  acid  from  4  to  9  per  cent.,  and  the  potash 
from  2  to  10  per  cent.  All  of  these  potato  fertilizers  could  not 
have  been  the  best  for  the  farmer  to  purchase.  The  manu- 
facturers evidently  cater  to  the  trade  and  some  of  them  put  out 
2  to  4  brands  so  as  to  be  able  to  sell  one  of  them  to  the  farmer, 


A    n:\N'     RlCMAKKS    AltOlTT     K  KKT  11,1/ I'.KS  1^5 

the  brand  depending  upon  the  price  the  farmer  is  vviUing  to  pay. 
Many  of  these  fertiHzers  were  high  grade  but  the  farmer  should 
consult  the  plant  food  guarantee  and  not  the  name  in  selecting 
fertilizer.  Those  that  were  sold  for  corn  and  potato,  tobacco  and 
potato,  vegetables,  root  crops  and  potatoes,  etc.,  either  do  not 
meet  the  requirements  of  these  crops,  or  else  the  purchaser  is 
wasting  money  in  buying  excesses  of  plant  food. 

Some  manufacturers  put  out  two  or  three  different  brands  made 
from  the  same  goods  and  guaranteed  the  same.  Thus  we  will 
find  Dixie  Cotton  Fertilizer  and  Corn  King  Guano  on  the  market 
with  the  same  guarantee  bagged  from  the  same  pile  of  goods,  and 
sold  for  different  crops.  Sometimes  two  different  brand  names 
are  used  for  the  same  material  to  be  sold  for  one  crop.  For 
example,  Golden  Imperial  and  Special  Mixture  may  be  sacked 
from  the  same  material,  carry  the  same  guarantee,  and  be  sold 
for  one  crop.  The  writer  has  seen  two  agents,  one  a  merchant 
and  the  other  a  farmer,  selling  the  same  fertilizer  under  different 
names  in  the  same  village.  The  farmer,  who  was  the  least  suc- 
cessful in  disposing  of  his  lot  thought  and  I  guess  still  thinks 
that  the  merchant  had  a  better  brand.  These  fertilizers  of  course 
sold  for  the  same  price  and  the  merchant  sold  three  times  as 
nmch  as  the  farmer,  because  he  was  a  bit  more  popular  and  had  a 
better  stand.  So  you  see  the  brand  name  helps  to  sell  fertilizer. 
The  farmer  should  buy  on  the  plant  food  content  and  not  by  the 
name  or  per  ton. 

The  manufacturers  also  often  sell  superphosphates  made  from 
rock  phosphates  under  the  name  of  dissolved  bone,  and  mixtures 
of  superphosphates  (made  from  rock)  and  potash,  as  dissolved 
bone  and  potash.  We  have  learned  that  dissolved  bone  contains 
nitrogen  and  phosphoric  acid  and  superphosphates  made  from 
rock  only  carry  phosphoric  acid.  So  when  dissolved  bone  or  a  dis- 
solved bone  and  potash  are  sold  without  any  nitrogen  guaranteed 
you  can  rest  assured  that  the  material  was  made  from  rock. 
However,  the  soluble  phosphoric  acid  from  rock  superphosphates 
is  just  as  valuable  as  that  from  dissolved  bone,  and  the  reverted 
is  ])erhai)s  about  equalh-  valuable  from  these  two  phosjihates.* 

lo 


136  FERTILITY   AND  FERTILIZER   HINTS 

How  to  Purchase  a  Fertilizer. — Some  time  before  you  intend 
to  purchase  your  fertilizer  write  to  your  Experiment  Station  or 
State  Board  of  Agriculture  for  bulletins  on  the  crops  you  in- 
tend to  raise  and  also  for  a  fertilizer  bulletin.  These  bulletins 
may  be  had  free  of  charge.  Study  these  bulletins.  In  the 
bulletins  on  crops  you  will  no  doubt  learn  the  plant  food  require- 
ment, that  is,  the  amounts  and  kinds  of  plant  food  most  suitable 
for  the  crops  you  are  interested  in.  The  fertilizer  bulletin  will 
no  doubt  acquaint  you  with  some  timely  suggestions  on  how  to 
purchase  fertilizers  and  will  also  give  you  the  names,  guarantees, 
analyses,  and  valuations  of  the  fertilizers  sold  in  your  state. 
You  can  in  all  probability  select  a  fertilizer  that  will  meet  your 
requirements.  If  any  element  as  nitrogen,  phosphoric  acid,  and 
potash  is  not  needed,  do  not  waste  your  money  by  purchasing 
a  complete  fertilizer  but  select  one  that  contains  the  constituents 
you  need  and  in  the  form  or  forms  you  desire.  You  are  now 
ready  to  talk  business  with  your  merchant  or  dealer.  Find  out 
from  him  if  he  has  the  particular  fertilizer  you  wish.  Perhaps 
he  has  not  it  in  stock  and  he  will  no  doubt  tell  you  he  has  some- 
thing just  as  good.  If  the  amount  and  kind  of  plant  food  that 
you  wish  is  present  in  the  brand  that  he  has,  why  it  is  just  as 
good  and  if  not  it  is  not  what  you  want.  No  doubt  the  factory 
for  which  he  is  agent  puts  out  a  fertilizer  of  the  composition 
you  desire ;  you  can  find  this  out  by  referring  to  your  fertilizer 
bulletin.  If  so,  you  may  be  able  to  get  your  merchant  to  order 
it  for  you.  If  his  factory  has  not  got  it  buy  from  one  that  has. 
You  have  your  fertilizer  bulletin  and  you  can  easily  write  for 
your  fertilizer  and  perhaps  save  the  agent's  profit. 

Study  the  Guarantee. — You  have  learned  that  many  of  the 
fertilizer  materials  as  cotton-seed  meal,  tankage,  bone-meal,  dry 
ground  fish,  etc.,  do  not  always  contain  the  same  amounts  of 
fertilizer  constituents  and  are  quite  variable  in  composition. 
Therefore  do  not  buy  any  of  these  products  just  because  they 
are  so  named.  Consult  the  guarantee  and  find  out  how  much 
plant  food  is  oflfered  for  a  certain  price.* 

Fertilizers  Should  Reach  their  Guarantees. — The  manufacturers. 


A    FKW    REMARKS    ABOUT    FERTILIZERS  1 37 

as  a  whole,  are  endeavoring  to  do  an  honest  business.  In  mak- 
ing their  mixtures  they  aim  to  give  a  little  more  plant  food  than 
they  guarantee,  so  that  the  fertilizer  will  meet  the  guarantee 
under  reasonable  conditions.  The  bulletins  of  the  different 
states  setting  forth  the  results  of  fertilizer  inspection,  show  that 
the  majority  of  the  factory  mixed  fertilizers  exceed  the  guar- 
antee. But  sometimes  fertilizers  fail  to  reach  the  guarantee 
in  all  constituents.  Factory  mixed  fertilizers  often  fall  below 
the  guarantee  in  one  element  but  exceed  the  guarantee  in  other 
elements  so  that  the  relative  value  is  above  the  guaranteed  value. 
Of  course  the  manufacturer  should  furnish  the  consumer  with 
fertilizer  that  reaches  its  guarantee  in  all  elements  as  the  pur- 
chaser has  a  right  to  expect  this.  Such  variation  is  often  due 
to  poor  mechanical  mixture  as  the  manufacturer  usually  puts 
in  enough  of  the  raw  materials  to  exceed  the  guarantee  in  all 
constituents.  When  a  shipment  of  fertilizer  fails  to  meet  its 
guarantee  in  one  or  more  elements,  and  runs  above  the  guarantee 
ir.i  one  or  more  elements,  the  purchaser  should  give  the  manu- 
facturer some  consideration  and  settle  on  an  equitable  basis 
and  allow  the  manufacturer  for  whatever  excess  that  may  be 
present  in  any  of  the  elements,  within  reasonable  limits.  If  the 
purchaser  contracts  for  a  certain  amount  or  amounts  of  con- 
stituents and  they  fall  materially  below  the  guarantee  a  rebate 
should  be  demanded.* 

Fertilizers  do  not  Deteriorate  Much  on  Standing. — The  mixed 
fertilizers  and  the  raw  materials  do  not  change  much  when 
kept  in  dry  storage.  The  mixed  fertilizers  are  usually  com- 
pounded from  materials  that  do  not  attack  and  set  free  the 
nitrogen  present.  The  soluble  phosphoric  acid  may  revert  and 
change  to  insoluble  phosphoric  but  not  to  any  appreciable  ex- 
tent. Therefore  should  a  farmer  have  some  fertilizer  left  over 
from  a  past  season  he  may  rest  assured  that  it  is  still  valuable 
provided  it  has  been  kept  in  a  dry  place.  If  fertilizer  gets  wet 
from  rain  or  becomes  very  moist  from  any  cause,  there  may  be 
considerable  losses  of  plant   food.* 

The  Time  to  Apply  Fertilizer. — Nitrate  of   soda,   sulphate  of 


138  FERTILITY   AND  FERTILIZER    HINTS 

ammonia,  and  calcium  nitrate  are  soluble  in  water  and  are  not 
fixed  in  the  soil.  They  should  be  applied  in  small  quantities  and 
at  the  proper  time,  or  when  nitrogen  is  needed,  to  give  the 
best  results.  When  large  applications  of  these  materials  are 
made,  some  of  the  nitrogen  may  be  lost  by  leaching.  These 
fertilizer  materials  should  never  be  worked  into  the  soil  too 
deeply  as  they  may  be  lost  by  leaching  before  the  plant  can 
appropriate  them.  The  organic  materials  furnishing  nitrogen 
all  have  to  be  oxidized  and  converted  into  nitrates  before  they 
may  readily  be  acquired  as  plant  food.  These  materials  may  be 
applied  early  enough  so  that  they  may  be  acted  upon  by  the  soil 
organisms  and  partially  decomposed  to  furnish  food  for  the 
young  plant.  The  very  slowly  available  organic  substances 
will  of  course  be  decomposed  more  slowly  than  dried  blood,  cot- 
ton-seed meal,  tankage,  steamed  horn  and  hoof  meal,  castor 
pomace  and  similar  substances.  One  of  the  functions  of  nitro- 
gen is  to  produce  growth.  It  would  be  wasteful  to  apply  any 
nitrogenous  substance  to  hasten  maturity.  It  seems  almost  un- 
necessary to  make  this  statement  but  some  farmers  use  nitrate 
of  soda  late  in  the  season  to  help  fill  out  ears  of  corn  after  the 
crop  has  been  made.  If  nitrate  of  soda  is  added  in  the  middle 
of  the  growing  period  before  the  ears  are  formed  it  will  help  to 
produce  more  vigorous  growth.  Generally  speaking,  the  nitrog- 
enous fertilizers  may  be  applied  in  the  spring  at  planting  time 
and  during  the  growing  period  when  needed. 

Phosphoric  acid  is  readily  fixed  in  the  soil.  When  soluble 
phosphoric  acid  is  added  from  superphosphates,  it  becomes  well 
distributed  in  the  soil,  because  of  its  fine  mechanical  condition, 
and  changes  to  insoluble  forms  which  are  not  apt  to  be  lost  by 
leaching.  Superphosphates  are  very  beneficial  to  young  crops 
and  tend  to  produce  strong  plants  that  can  better  resist  the 
attacks  of  fungi  and  insects.  Superphosphates  may  be  applied 
before  or  during  planting  time.  Raw  bone-meal  and  ground 
rock  phosphate  may  be  applied  at  most  any  tiine  because  they 
are  slowly  available :  but  other  fertilizers  carrying  phosphoric 
acid  in  the  available  form  should  be  applied  just  before,  or  at 
planting  time. 


A    Fi;\V    REMARKS    AP.OUT    !•  KRTILI/.KRS  139 

Potash  is  very  (luickly  tixod  in  the  soil  by  the  double  silicates, 
so  that  it  is  difficult  to  distribute  it  evenly.  Potash  may  be 
applied  sometime  before  planting  so  that  the  plowing  and  har- 
rowing may  help  to  mix  it  with  the  soil  and  insure  a  uniform 
distribution. 

In  mixed  fertilizers  we  have  found  that  any  combination'  of 
fertilizer  materials  may  enter  into  their  composition.  There 
may  be  nitrate  of  soda,  organic  materials,  superphosphates,  and 
potash  salts  present  in  these  fertilizers  and  so  in  the  application 
of  them  we  must  consider  the  properties  of  all  the  fertilizer 
materials.  It  is  generally  best  to  apply  these  fertilizers  in  the 
spring.  Sometimes  an  additional  application  during  the  grow- 
ing period  will  help  to  force  the  crop.  When  much  fertilizer 
is  to  be  applied,  especially  on  sandy  soils,  part  of  it  may  be 
applied  in  the  spring  and  part  later  on  when  the  cro])  may  be 
backward  or  need  forcing. 

Crops  like  wheat  which  are  sown  in  the  fall  need  fertilizer 
at  that  time  and  also  a  light  dressing  of  some  nitrogenous  fer- 
tilizer in  the  spring  to  help  it  recover  from  the  winter.  Some 
of  the  market  garden  crops  require  fertilizer  at  planting  time 
and  at  short  intervals  during  the  growing  period. 

How  Fertilizers  are  Applied. — Fertilizers  are  usually  broad- 
cast, partly  broadcast  and  partly  in  the  drill  or  hill,  and  in  the 
drill  or  hill.  When  heavy  applications  are  applied,  broadcast- 
ing is  perhaps  the  best 'method.  The  fertilizer  may  be  applied 
after  the  last  plowing  and  harrowed  into  the  top  part  of  the  sur- 
face soil  with  a  wheel  harrow  or  some  kind  of  a  cultivator.  In 
this  way  the  fertilizer  will  become  well  mixed  with  the  soil.  If 
a  broadcast  distributor  is  not  used,  one-half  of  the  fertilizer 
may  be  applied  by  walking  north  and  south  and  the  other  half 
by  walking  east  and  west.  In  this  way  the  fertilizer  should  be 
imiformly  applied.  When  home  mixtures  containing  farm 
manure  or  fertilizers  mixed  with  manure  are  used,  the  manure 
spreader  may  be  employed  to  distribute  the  fertilizer. 

Some  farmers  apply  fertilizer  partly  by  broadcasting  and  part- 
ly in   the  drill  or  hill.     This  is  an  excellent  practice    for  some 


I40  FERTILITY   AND   FERTILIZER    HINTS 

crops  and  on  some  soils.  That  which  is  applied  in  the  drill  or 
hill  furnishes  plant  food  during  the  first  growth  before  the  roots 
are  developed  and  that  which  is  sown  broadcast  helps  the  later 
growth  when  the  roots  spread  out.  In  this  system  of  applying 
fertilizers  it  is  perhaps  better  to  apply  most  of  the  fertilizer 
broadcast.  When  farm  manure  is  used  it  may  all  be  spread 
broadcast  and  the  fertilizer  used  to  supplement  it,  which  is  no 
doubt  quick  acting,  put  in  the  drill  or  hill.  Potatoes,  corn  and 
market  garden  crops  are  often  fertilized  in  this  way. 

With  small  grain,  roots  and  other  crops  with  small  root 
systems,  fertilizers  are  often  applied  wholly  in  the  drill  or  hill. 
Great  care  should  be  taken  in  applying  fertilizer  in  this  way  to 
keep  the  fertilizer  away  from  the  seed.  Most  fertilizers  contain 
some  nitrate  of  soda,  potash  salts,  or  other  materials  that  will 
injure  the  seed  if  they  come  in  contact  with  it.  Therefore  a 
little  earth  should  separate  the  seed  from  the  fertilizer.  The 
fertilizer  distributors  usually  cover  the  fertilizer  sufficiently  to 
protect  the  seeds.  When  fertilizer  is  applied  in  the  hills  it 
should  be  spread  over  the  place  where  the  hill  is  to  be  and  not 
applied  all  in  one  place.  Earth  should  be  spread  over  it  as  in 
drill    application. 

When  fertilizer  is  to  be  applied  during  the  growing  season 
it  may  be  distributed  on  both  sides  of  the  plants  to  the  center 
of  the  row  and  worked  in  with  a  cultivator.  On  many  hoed 
crops  this  method  is  used.  It  is  also  advisable  on  light  soils 
that  are  subject  to  leaching.  On  these  soils  sufficient  fertilizer 
may  be  applied  at  planting  time  to  give  the  crop  a  start  and  the 
remainder  during  those  periods  in  the  growing  season  when 
the  crop  needs  nourishment  or  wishes  to  be  forced  for  an  early 
market. 

When  fertilizers  are  applied  to  trees  and  bushes  they  should 
be  distributed  in  a  circle  around  the  tree ;  the  radius  of  which 
is  equal  to  the  height  of  the  tree  or  bush.  They  should  be 
worked  into  the  soil  by  shallow  cultivation.  The  feeding  roots 
of  many  trees  are  near  the  surface  and  extend  to  quite  a  dis- 
tance  from  the  base  of  the   tree   so  that  by  applying  the   fer- 


A    FEW    REMARKS    ABOUT    FERTILIZERS 


141 


tilizer  for  some  distance  from  the  tree,  the  roots  are  better  able 
to  assimilate  it  and  the  soil  organisms  which  render  it  avail- 
able can  act  upon  it  more  readily. 

It  is  Profitable  to  Use  Fertilizers? — Every  farmer  should  be 
able  to  decide  this  question  for  himself.  The  nature  of  the 
crop  and  the  condition  and  fertility  of  the  soil  will  determine 
whether    fertilizers    should    be    used.     If    extensive    farming    is 


1 

p«»*'^\  j^'^If     :^L^Iw^^^Sik 

i^ 

1 

^Bm\:L  v^iS^KiMM  '^  WKmaS^^ 

1^ 

Fig.  12.  — Liberal  fertilization  is  usually  profitable  when  growing  truck  crops. 

practiced  and  large  crops  are  grown  on  small  areas  fertilizers 
are  generally  required.  Market  garden  and  truck  crops  general- 
ly more  than  pay  for  the  liberal  use  of  fertilizer.  When  market 
garden  and  truck  crops  are  grown  on  high  priced  land  large 
applications  of  fertilizer  are  necessary  to  produce  maximum 
crops  to  insure  profitable  returns  on  the  investment.  In  some 
sections  potatoes,  onions,  tobacco,  oranges,  and  other  crops  re- 
ceiving large  amounts  of   fertilizer  give  profitable   returns. 


142  FKRTILITV   AND   FERTILIZER    HINTS 

If  the  soil  is  kept  in  good  physical  condition  the  use  of  ferti- 
lizers is  more  profitable  than  on  soils  not  properly  cared  for. 
On  poor  soils  the  use  of  fertilizers  is  necessary  for  crop  pro- 
duction, for  without  them  a  profitable  crop  cannot  be  produced. 
On  farms  where  a  systematic  rotation  is  practiced,  and  farm 
manures  and  green  manures  are  employed,  the  use  of  fertilizer 
to  supplement  the  deficiencies  of  the  soil  is  usually  very  pro- 
fitable, while  on  farms  where  one  crop  farming  is  continued,  the 
response  to  fertilizers  is  not  so  satisfactory.  The  farmer  can 
keep  his  soil  in  good  condition  and  profit  by  the  use  of  fertilizers. 
Fertilizers  .should  not  always  be  blamed  for  unprofitable  re- 
turns as  the  trouble  generally  rests  with  the  farmer  who  is  care- 
less in  his  methods.  Farmers  should  spend  a  great  deal  of  time 
tilling  the  soil  and  not  expect  the  fertilizer  to  do  all  the  work. 

Sometimes  fertilizers  do  not  prove  profitable  because  the  soil 
is  acid  or  too  alkaline.  If  these  conditions  are  corrected  the 
use  of  fertilizers  is  often  profitable. 

It  should  be  remembered  that  some  fertiHzers  like  raw  bone- 
meal,  ground  rock  phosphate,  etc.,  do  not  give  up  all  of  their 
plant  food  during  the  first  season  but  may  help  the  crops  for 
two  or  three  years  and  prove  profitable  in  this  way. 

Amount  of  Fertilizer  to  Use. — Enough  fertilizer  should  be  used 
to  produce  profitable  crops.  This  amount  depends  upon  a  great 
many  factors,  as  the  system  of  farming,  the  nature  of  the  soil, 
the  crop  to  be  raised  and  its  value,  the  fertility  of  the  soil, 
the  value  of  the  land,  etc.  Frequent  light  applications  are  usual- 
ly more  profitable  than  occasional  heavy  applications.  Market 
garden  and  truck  crops  require  more  fertilizer  than  the  staple 
crops.  From  500  to  2,500  pounds  of  fertilizer  are  used  for 
market  garden,  truck  and  special  crops,  and  300  to  1,000  pounds 
for  the  staple  crops,  unless  previous  experience  has  shown  that 
more  or  less  than  these  amounts  are  necessary  and  profitable. 

The  following  table  shows  in  pounds  per  acre  the  quantities 
of  the  elements  suggested  for  use  in  available  form,  in  fertilizers 
for  the  crops  indicated.* 


Crops 


Nitrogen 


Alfalfa \  5-IO 

Apples I  8-16 

Asparagus |  20-40 

Barley 1 2-24 

Beans 5-10 

Beets 20-40 

Blackberries 15-30 

Buckwheat 15-30 

Cabbage 40-80 

Carrots ;  15-30 

Cauliflower  40-80 

Celery !  40-80 

Cherries I  10-20 

Clover 5-10 

Corn !  10-20 

Cucumbers j  30-60 

Currants 10-20 

Egg  plant 40-80 

Flax \  1 0-20 

Gooseberries 1 0-20 

Grapes 8-16 

Grass  for  pastures 15-30 

Grass  for  lawns 20-40 

Grass  for  meadows 15-30 

Hops ,  20-40 

Horse-radish 1 5-30 

Lettuce 40  80 

Millet  I  J5-30 

Muskmelons j  30-60 

Nursery  stock j  jo-20 

Oats j  1 2-24 

Onions 45-90 

Parsnips I  20-40 

Peaches 15-30 

Pears '  8-16 

Peas 5-10 

Plums 10-20 

Potatoes 30-60 

Pumpkins i  30-60 

Quinces-  •  •    8-16 

Radishes i  15-30 

Raspberries 1 2-24 

Rye 12-24 

Sorghum 10-20 

Spinach 15-30 

Squashes 30-60 

Strawberries 25-50 

Tobacco 30-60 

Tomatoes 25-50 

Turnips 2040 

Watermelons '  30-60 

Wheat j  1 2-24 


'  Bui,  169,  Kansas  Experiment  Station. 
'-'  To  change  phosphorus  to  phosphoric  acid,  njultiply  by  2 
to  potash,  multiply  by  1.2. 


Phosphorus'- 

Potassium'-' 

12.5-25 

30-  60 

12.5-25 

40-  80 

12.5-25 

30-  6u 

8.5-17 

20-  40 

12.5-25 

3..-  6c, 

10-20 

30-  60 

12.5-25 

30-  6t) 

12.5-25 

30-  60 

30-60 

75-150 

15-30 

35-  70 

30-60 

75-150 

20-40 

50-100 

15-30 

35-  70 

■2.5-25 

30-  60 

15-30 

25-  50 

20-40 

50-1  ex. 

10-20 

30-  60 

20-40 

75-150 

10-20 

25-  50 

IO-21) 

30-  60 

12.5-25 

35-  70 

12.5-25 

30-  60 

10-20 

25-  50 

'2.5-25 

30-  60 

15-30 

80- 1 6c. 

10-20 

30-  60 

20-40 

60-120 

■2.5-25 

30    60 

20-40 

50- UK. 

10-20 

25-  50 

8.5-17 

25-  50 

25-50 

70-140 

25-50 

40-  80 

17.5-35 

45-  90 

12.5-25 

40-  80 

'2.5-25 

30-  60 

I5-.SO 

35-  70 

'7.5-35 

55-110 

20-40 

50-100 

1 2  5-25 

40-  80 

15-30 

35-  70 

'7.5-35 

50-100 

8.5-17 

25-  50 

15-30 

25-  50 

25-50 

35-  70 

20-40 

50-100 

25-50 

60-120 

20-40 

60-120 

15-30 

30-  60 

10-20 

30-  60 

20-40 

50-Kxj 

8-5-17 

lo-  20 

y  2.T,.  and  to  conve 

t  potassium 

144  FERTIUTY   AND  FERTILIZER   HINTS 

NOTES. 

The  following  notes  refer  to  tables,  experiments,  statistics, 
discussions  and  other  interesting  data  that  may  be  found  in 
Halligan's  Soil  Fertility  and  Fertilizers  : 

Page  3— A  discussion  on  evidence  to  show  that  other  plants  gather  nitro- 
gen trom  the  air. 
Page  5— Distribution  of  elements  in  the  earth's  crust  and  air;  composition 

of  the  air. 
Page  8 — Table  showing  the  elements  that  make  up  plants. 
Page  9  —The  distribution  of  the  mineral  elements  in  plants  and  a  full  dis- 
cussion of  the  ash  in  plants. 
Page  II — The  per  cent,  of  ash  and  the  mineral  elements  that  constitute  the 

ash  are  given  for  several  vegetable  substances. 
Page  14 — Table  of  the  amount  of  plant  food  in  typical  American  soils  from 

different  states. 
Page  15— Estimates  of  plant  food  in  soils  with  yields  of  crops. 
Page  18 — Table  of  temperatures  of  different  classes  of  soils. 
Page  18 — The    average  mean  monthly  range  in  temperature  of  the  air  and 

soil  for  twelve  years  at  Lincoln,  Nebraska. 
Page  18— Standard   measurements  of  soil  particles  and  mechanical  analyses 

of  soils. 
Page  19— Table  of   chemical  and  mechanical  composition  of  different  types 

of  soils. 
Page  21 — Table  showing  the   upward  movement  of  water  in  different  types 

of  soils. 
Page  22— A  table  showing  the  number  of  bacteria  found  in  a  gram  of  soil 

during  some  part  of  the  growing  period. 
Page  22— Two   tables   that  demonstrate  how  manure  helps  nitrification  at 

different  periods  of  the  growing  season. 
Page  26 — Composition  of  drainage  waters  from  plots  of  a  wheat  field. 
Page  26— Table  giving  the  amounts  of  nitrogen  removed  by  different  farm 

crops. 
Page  27— Data    showing  the  amount  of  nitrogen  lost  from  bare  soils  and 

wheat  land  ;  comments  on  the  same. 
Page  34 — Data  concerning  the  effect  of  a  rotation  of  crops  on  the  humus 

supply. 
Page  34 — Crop  rotations  practiced  in  different  sections  of  the  United  States. 
Page  34— Fertility  removed  by  farm  produce  ;  loss  of  fertility  by  exclusive 

grain  farming  and  stock  farming. 
Page  36— Tables    showing    actual  results  obtained  from  different  kinds  of 

animals  performing  different  kinds  of  work  on  the  value  of  manure. 
Page  36 — Composition  of  straws,  leaves  and  sawdust. 


NOTICS  145 

I'age  37 — Data  given  the  Hiiiount  of  manure  produced  by  the  horse  per 
year,  the  composition,  and  the  amount  of  straw  necessary  to  absorb 
the  liquid  portion.  Also  data  on  the  amount  of  manure  produced  by 
the  cow  and  the  hog,  and  the  composition  of  these  manures. 

Page  38 — The  amount  of  manure  produced  by  the  sheep  per  year,  its  com- 
position, and  the  amount  of  straw  necessary  to  absorb  the  liquid 
portion. 

Page  39 — Composition  of  hen,  fowl  and  bat  manures ;  amount  of  manure 
produced  by  different  kinds  of  fowl. 

Page  39  — Experiments  by  feeding  steers  different  feeds,  giving  the  varia- 
tions in  the  nitrogen  content  of  the  manure  produced  and  the  crop 
returns  from  these  manures.  Table  and  discussion  on  the  commercial 
value  of  manure. 

Page  40 — Results  of  experiments  on  the  lasting  effects  of  manure  for  a 
period  covering  many  years  and  the  yield  of  crops  from  manured  and 
unmanured  plots. 

Page  41 — Tables  and  data  showing  the  losses  by  leaching  on  horse  manure, 
cow  manure,  and  a  mixture  of  horse  and  cow  manure. 

Page  42 — Table  of  composition  of  gases  in  manure  heaps  and  the  effect  of 
keeping  manure  heaps  moist. 

Page  45— The  percentage  of  water  in  unmanured  and  manured  wheat  and 
barley  fields,  together  with  considerable  discu-ssion  on  the  losses  and 
retention  of  water  in  these  fields.  Also,  the  effect  of  manure  in  dry 
and  wet  seasons,  on  the  yield  of  crops  for  51  years. 

Page  50 — A  description  of  the  process  employed  in  manufacturing  cotton- 
seed meal. 

Page  50— Commercial  classification  of  cotton-seed  meal. 

Page  52 — A  description  of  rape  meal. 

Page  54 — Another  method  used  in  treating  horns  and  hoofs.  The  produc- 
tion of  fertilizers  by  packing  houses. 

Page  56 — Analyses  of  nitrogenous  guanos,  with  a  list  of  the  deposits  that 
have  been  and  are  being  worked,  with  comments  on  guanos. 

Page  57 — Composition  of  bat  guanos. 

Page  57 — New  process  for  recovery  of  ammonia  from  coal.  Extent  of 
manufacture  of  ammonium  sulphate. 

Page  57 — How  to  detect  adulteration.  Table  showing  percentages  of  ammo- 
nia, pure  ammonium  sulphate,  nitrogen  and  possible  impurities  in 
commercial  sulphate  of  ammonia. 

Page  58 — Origin  of  deposits,  amounted  exported  to  date,  value  of,  process 
of  manufacture,  and  analyses  of  ciystals. 

Page  58 — Effect  of  continued  u.se  of  nitrate  of  soda. 

Page  59 — A  full  description  of  the  process  of  manufacture,  output  and 
value,  and  comments  on  calcium  nitrate. 

Page  59 — The  process  of  manufacture,  composition  and  comparative  experi- 
ments with  ammonium  sulphate  are  given. 


146  FERTIUTY   AND  FERTILIZER   HINTS 

Page  59— Table  of  composition  of  high  grade  nitrogenous  products. 

Page  62— A  full  description  of  wool  waste,  shoddy,  etc. 

Page  63 — A  more  complete  discussion  on  garbage  tankage. 

Page  64 — Vegetation  and  laboratory  experiments  with  several  high  and  low 
grade  nitrogenous  substances.  Also  a  description  and  discussion  of 
these  materials. 

Page  67 — Statistics  giving  the  amounts  of  nitrogenous  materials  used  in 
manufacturing  commercial  fertilizers  for  1900  and  1905.  The  total 
ammonia  contained  in  manufactured  fertilizers  ;  nitrogen  removed  by 
different  farm  crops. 

Page  68 — Table  showing  the  value  of  nitrogen  in  increasing  yields  for  a 
period  of  56  years,  with  a  discussion  of  the  same. 

Page  70 — Composition  of  raw  bones. 

Page  71— Composition  of  good  and  poor  steamed  bone-meals. 

Page  71 — Composition  of  raw  and  steamed  bones  for  comparison. 

Page  72 — Seven  analyses  of  bone-black  from  sugar  refineries. 

Page  72— Comparison  of  bone-ash,  commercial  bone-ash,  pure  o.x  bone-ash, 
horse  shank  bone-ash,  ox  bone-ash. 

Page  73 — A  complete  discussion  of  the  phosphate  deposits  in  the  United 
States  with  statistics  and  tables  on  total  production  and  individual 
production,  market  value,  estimated  life  of,  utilization,  exports,  devel- 
opment, Western  deposits,  and  other  interesting  data. 

Page  74 — Analyses  of  South  Carolina  phosphates. 

Page  74 — A  description  of  how  Florida  phosphates  are  mined.  Analyses  of 
Florida  phosphates. 

Page  75— Analyses  of  brown,  blue  and  white  rock. 

Page  75 — Analyses  of  Canadian  apatite. 

Page  76 — Composition   of  basic  slag  and  comments  on. 

Page  76  — List  of  phosphatic  guano  deposits,  including  those  that  have  been 
and  are  being  worked  ;  analyses  of  these  guanos. 

Page  79— Influence  of  degree  of  fineness  on  value  of  phosphates,  with 
experimental  results. 

Page  83 — A  complete  description  of  the  form  of  phosphoric  acid  in  basic 
slag  and  its  availability. 

Page  83— Amounts  of  acid  to  dissolve  phosphates  ;  the  reversion  of  phos- 
phoric acid. 

Page  85 —Classification  of  terms  used  for  available  and  total  phosphoric 
acid  ;  amount  of  available  phosphoric  acid  contained  in  manufactured 
fertilizers. 

Page  87 — Average  composition  of  superphosphates  and  double  superphos- 
phates. 

Page  88— Amounts  of  phosphates  used  for  manufacturing  fertilizers.  Phos- 
phoric acid  removed  by  crops. 

Page  89— Experiments  showing  the  fixation  of  phosphoric  acid.  Discus- 
sion on  the  absorption  of  phosphoric  acid. 


NOTKS  147 

Page  89 — Experiments  showing  the  effect  of  phosphoric  acid. 

Page  89 -Crop  returns  from  phosphatic  fertilizers,  with  and  without  lime 
on  several  crops  ;  summary  of  these  results. 

Page  90 — A  full  description  of  the  potash  mines  and  the  several  salts 
deposited. 

Page  91— Composition  of  kainit  and  a  more  complete  description  of  it. 

Page  91 — Composition  of  .sylvinit  and  a  more  complete  description  of  it. 

Page  91 — Composition  of  muriate  of  potash  and  a  more  complete  descrip- 
tion of  it. 

Page  92 — Composition  of  potassium  sulphate  and  a  more  complete  descrip- 
tion of  it. 

Page  92 — Composition  of  double  sulphate  of  potash  and  magnesia. 

Page  93 — Composition  of  potash  manure  salts. 

Page  93— Composition  of  potash — magnesium  carbonate. 

Page  93 — Table  of  composition  of  Stassfurt  potash  salts.  Production  of 
crude  and  manufactured  salts,  and  consumption  of  the  same. 

Page  93— Analyses  of  leached  and  unleached  ashes  from  several  sources; 
amounts  of  ingredients  in  different  kinds  of  wood. 

Page  94 — Discussion  and  analyses  of  tobacco  stems,  stalks  and  wastes. 

Page  94 — Composition  of  cotton-seed  hull  ashes  and  a  discussion  of  this 
product. 

Page  94 — Full  discussion  of  the  manufacture  of  this  product. 

Page  94 — Composition  of  beet  molasses  ash  and  fertilizer  by-products  made 
from  it.  Wine  residue  fertilizers.  Statistics  giving  actual  potash  ma- 
terials and  actual  potash  contained  in  manufactured  fertilizers. 
Amounts  of  potash  removed  by  different  farm  crops.  Crop  producing 
value  of  different  potash  salts. 

Page  97— Experiments  and  discussion  showing  the  effect  of  potash  on  dif- 
ferent kinds  of  crops. 

Page  99 — Comments  on  seaweed  and  its  preservation.  Analyses  of  differ- 
ent varieties.     Comments  and  analyses  of  .seaweed  ash. 

Page  99 — Analyses  of  different  kinds  of  marl  and  comments  on  the  benefit 
of  this  material. 

Page  99— Several  analyses  of  peat  and  muck.     Liquid  and  flower  fertilizers. 

Page  100 — Analyses  of  commercial  pulverized  sheep  manures. 

Page  100— A  full  discussion  of  these  fish  wastes  and  analyses  of  the  same. 

Page  100 — Analyses  of  human  excreta  and  sewage  sludge,  together  with  a 
complete  discussion  of  sewage  aud  sewage  sludge. 

Page  loi— Analyses  and  discussion  on  all  the  ashes. 

Page  loi  —Leather  scrap  ashes,  ivory  dust  and  spent  hops  are  di.scussed. 

Page  loi — Analyses  of  soot. 

Page  102 — A  more  complete  description. 

Page  102— Experiments  with  silicate  of  potash  and  a  discussion  of  its  value 
aud  output. 

Page  102 — Analyses  and  discussion  of  salt. 


148  FERTILITY  AND  FERTILIZER   HINTS 

Page  103 — Full  comment  on  sulphates  of  soda  and  magnesia. 

Page  104—  Representation  of  the  forms  of  lime,  sources  of  carbonate  of  lime, 
and  analyses  of  lime  and  limestone. 

Page  106— Experiments  showing  the  effect  of  the  form  of  lime  on  crop  pro- 
duction, the  fertility  of  the  soil,  and  on  soils  rich  in  organic  matter. 

Page  106 — Amounts  of  lime  removed  by  crops  ;  amount  of  lime  in  soils. 

Page  107— An  extensive  article  on  the  acidity  of  upland  soils,  including 
observations  on  growing  plants,  effect  of  lime  in  conjunction  wiih 
nitrate  of  soda  and  ammonium  sulphate. 

Page  108— Analyses  of  gas  lime. 

Page  108 — Analyses  of  gypsum  ;  effect  of  gypsum  on  clover  ash  and  discus- 
sion. 

Page  io9~Fertility  restored  b}^  some  plants  ;  amount  of  nitrogen  obtained 
from  the  air. 

Page  112 — Statistics  given  the  cost  of  manufacture,  cost  of  products,  number 
of  tons  manufactured,  consumption  and  distribution  of  fertilizer  by 
states. 

Page  114 — Output  of  fertilizer  factories,  cost  of  nitrogen,  of  phosphoric  acid, 
and  of  potash  ;  classification  of  commercial  fertilizers. 

Page  116 — Discussion  of  the  requirements  of  fertilizer  laws,  comparison  of 
the  laws,  model  fertilizer  law,  comments  on  model  law,  tentative  defi- 
nitions of  fertilizers  and  of  misbranding  and  adulteration. 

Page  117— Converson  factors. 

Page  118— A  list  of  one  manufacturer's  brands  with  simplified  guarantees. 
Purity  of  raw  materials  as  a  basis  of  purchase. 

Page  T25— Commercial  values  of  tankage  and  bone.  Comments  regarding 
valuations.  Valuations  show  the  cost  of  plant  food.  Objections  to 
valuations.  Points  in  favor  of  valuations.  Valuations  in  other  states. 
Chapter  on  high,  medium  and  low  grade  fertilizers,  including  fillers, 
cost  of  different  grades,  the  100  per  cent,  of  fertilizers  and  other  inter- 
esting data. 

Page  128 — Amount  of  plant  food  purchased  for  I30  in  factory  and  home 
mixed  fertilizers.  Selling  prices  and  valuations.  Analyses,  cost,  and 
valuations  of  home  mixtures. 

Page  131— A  system  of  rebating  when  materials  fail  to  reach  the  guarantee. 

Page  133 — Home  mixture  formulas.  How  to  determine  the  requirements  of 
the  soil. 

Page  135 — Number  of  brands  sold  in  Georgia  for  several  years. 

Page  136— Examples  of  different  prices  for  grades  of  cotton-seed  meal  with 
comment. 

Page  137 — Fertilizer  recipes  or  patent  formulas  with  a  discussion  of  the 
same. 

Page  137 — Table  showing  results  on  fertilizers  kept  in  storage.  Incompati- 
bles  in  fertilizer  mixtures,  .showing  materials  that  may  and  may  not 
be  mixed  together. 


NOTES  149 

Page  142 — Chapter  giving  the  requirements  of  crops  classified  into  staple 
and  special  crops  ;  small  grains  ;  forage  crops  ;  market  garden  and 
truck  crops  ;  fruits  ;  nuts.  Fertilizer  formulas  for  the  several  crops 
grown  in  the  United  States. 

Appendix  includes  a  list  of  the  Experiment  Stations  ;  how  to  collect 
an  exhibit  of  fertilizer  materials  ;  fertilizer  constituents  in  feed  stuflfs; 
the  number  of  pounds  of  a  fertilizer  required  to  furnish  one  pound  of 
any  element  when  the  percentage  of  that  element  present  in  the 
fertilizer  is  known. 


INDEX 


Acid    phosphate,    So;    color    of,    87; 

manufacture   of,    80. 
Acidity    of    soils,    104 ;    how    to    lind 

out    when    soils    are    acid,    105. 
Acids  and  bases,  9. 
Aerobic    fermentation,    41. 
Agricultural    salt,    102. 
Agricultural  values  of  fertilizers,  121. 
Aluminum,    5. 
Ammonium  chloride,  103. 
Ammonium  nitrate,  102. 
Ammonium  sulphate,  composition  and 

availability    of,   57;    manufacture 

of,   57. 
Anaerobic   fermentation,  42. 
Apatite,    Canadian,    75. 
Ashes,    see    wood    ashes,    coal   ashes, 

etc. 
Ash  in  plants,  10,   11,  12. 
Azotin,  54. 

Bacteria,    number    in    the    soil,    22. 
Basic  slag,  75 ;  phosphate,  82. 
Bat  guano,  56. 
Bedding    for    litter,    36 ;     absorptive 

power  of,  36;   kind   and   amount 

used,  36. 
Beet  molasses  ash.  94. 
Beet  refuse,  6r. 
Blood,  dried,  52. 
Bone-ash,  72. 
Bone-black,  71. 
Bone-dust,  71. 

Bone-meal,    raw,    70 ;    steamed,    70. 
Bone  phosphates,   77. 
Bone  tankage,   72. 
Bones,    70 ;    inechanical    composition 

of,  71. 
Brand    and    trade    names    of    fertiliz- 
ers,  134. 
Brick  kiln   ashes,   loi. 
Calcium,  4;   sulphate   of,   81,    108. 


Calcium  cyanamid,  59;  fertilizing  val- 
ue of.  59;  properties  of,  59. 

Calcium  nitrate,  59. 

Calculation  of  amounts  from  known 
percentages,  132. 

Calculation  of  percentages  from 
known    amounts,    131. 

Capillary  water,  20;  amounts  of  held 
by  soils,  21 ;  how  to  increase  up- 
ward movement  of,  21 ;  how  to 
prevent  loss  of,  21. 

Carbon,  3. 

Carbonate   of   lime,    104. 

Carbonate  of  potash,  94. 

Carbonic    acid,    104. 

Castor   pomace,    52. 

Chemical  analyses,  interpretation  of, 
119;  examples  of.  119.  120.  121. 

Chemical    elements,    i 

Chemical   symbols,    i. 

Chlorine,  5. 

Coal  ashes,   100. 

Commercial  fertilizers,  chapter  on, 
112;  basis  of  purchase,  114: 
causes  for  large  consumption, 
112;  fertilizing  materials  used 
by  manufacturers,  114;  how  to 
lessen  use  of,  113;  ton  basis,  115; 
unit    system,     114. 

Commercial  values,  122;  how  to  cal- 
culate, 124. 

Compost,  98. 

Corn  cob  ashes,   lor. 

Cotton-seed,  yield  of  products  from, 
50. 

Cotton-seed   hull   ashes,   94. 

Cotton-seed  meal.  50:  composition  of, 
50;   value   of,   50. 

Cow   manure,  s~ ;  analysis  of,  39. 

Denitrification,  22. 

Diversification    of    crops,    29. 


152 


Double  sulphate  of  potash  and  mag- 
nesia, 92. 

Double  superphosphate,  86. 

Drainage,   20;    losses   from,   26. 

Dry  matter,  composition  of  in  plants, 
8. 

Elements  sometimes  lacking  in  the 
soil,  16;  obtained  from  air  and 
water,  16;  present  usually  in 
sufficient   amounts,    16. 

Erosion,    25 ;    ways   to    check,    25. 

Essential   elements,   16:   replacing  of, 

I/- 

Fallowing,   26. 

Farm  manures,  chapter  on,  35 ; 
amount  to  apply,  46;  analyses  of, 
39;  bacteriological  effect  of, 
46;  benefits  grass  land,  45:  care, 
preservation  and  use  of,  40 : 
composition  of  covered  and  un- 
covered, 44 :  composition  of  fresh 
and  rotted,  43 :  composting,  42 : 
conditions  affecting  value  of,  35  : 
effect  of  fresh  and  exposed  man- 
ure on  crop  production,  46 ;  effect 
of  kind  and  amount  of  bedding 
used  on  value  of,  36;  effect  of 
on  mangolds  with  other  ferti- 
lizers, 45 ;  effect  of  leaching  on, 
40;  effect  of  nature  and  amount 
of  feed  on,  39;  fermentations  in. 
41  ;  how  to  apply,  47 ;  how  to 
calculate  amount  produced,  39 : 
improves  the  texture  of  soil, 
45;  influence  of  age  of  animal 
on  value  of,  35 ;  influence  of 
use  of  animal  on  value  of,  33 : 
keep  manure  moist,  42;  kinds  of 
manure,  35 ;  lasting  effect  of,  40 ; 
physical  effects  of,  44;  preserva- 
tives, 44;  prevents  mechanical 
loss  by  winds,  45 ;  produces  a 
better  moisture  condition,  45 : 
store  under  cover,  43 :  time  to 
apply,  46:    waste   of,   40. 


l""eather   waste,   61. 

Fertilizers,  chapter  on,  112;  a  few 
remarks  about,  134;  agricultural 
values  of,  121 ;  amount  to  use, 
142;  brand  and  trade  names  of, 
134;  calculations  on,  131,  132; 
commercial  values  of,  122;  de- 
terioration of  on  storage,  137 ; 
elements  required  for  crops, 
table  of,  143 ;  how  applied,  139 ; 
how  to  purchase,  136 ;  is  it  profit- 
able to  use,  141  ;  time  to  apply, 
137;  trade  values  of,  123:  valua- 
tion of,  chapter  on,  119. 

Fertilizer   laws,    115. 

Fertilizer  materials,  low  grade,  value 
of,  64:  basis  of  purchase,  114; 
how  to  mix  it  at  home,  130:  how 
to  purchase,  130:  used  by  manu- 
facturers,   114. 

Filler.   1 28. 

Fish,   dry  ground,   54,   72. 

Fish  scrap,  fresh,   100. 

Formulas  for  crops,   143. 

Garbage  tankage,  63. 

Gas   lime.    107. 

(^.recn  manures,  108;  classes  of,  108: 
deep  rooted  plants  valuable,  in  : 
leguminous  crops  preferable  for. 
109;  the  best  time  to  grow,  no; 
the  best  time  to  plow  under,  109. 

Guanos,  how  deposited.  55:  nitrog- 
enous, 55 ;  phosphatic,  76. 

Guarantee  of  fertilizers,  116,  117,  118; 
examples  of,  116;  fertilizers 
should  reach  their  guarantees, 
136;  interpretation  of,  116:  mean- 
of,  116:  study  the  guarantee,  136. 

Gypsum,   81,    108. 

Hair   and   fur   waste,   61. 

Hen  manure,  39;   analysis  of,  39. 

Hog  manure.   38:   analysis  of,  39. 


153 


1  Ionic  mixtures,  chapter  dh,  i^O; 
calculations  of  percentages  and 
amounts  in  fertilizers,  131,  132; 
definitions,  126;  does  away  with 
the  purchase  of  unnecessary  con- 
stituents, 128;  manufacturers  al- 
low credit,  127 ;  manufacturers 
claims,  126;  mechanical  condi- 
tion of  factory  and  home  mixed 
fertilizers,  127;  mixed  fertiliz- 
ers compounded  for  the  crop, 
127;  mixed  fertilizers  more  easi- 
ly purchased,  127;  plant  food 
obtained  at  a  lower  price,  127; 
reasons  for  and  against  the  use 
of,   126. 

Horn  and  hoof  meal,  steamed,  54; 
untreated,  61. 

Horse  manure,   37 :   analysis   of,   39. 

Humus,  13. 

Hydrochloric   acid,    i. 

Hydrogen,  i. 

Hygroscopic  moisture,  6. 

Inorganic  matter,   13. 

Iron,  4. 

Iron   sulphate,    102. 

Kainit,   91. 

King  crab,  55. 

Leather  meal;  dissolved,  60;  raw, 
60;  treated,  60. 

Leaves  for  bedding,  36. 

Lime,  104 ;  amount  to  apply,  106 ; 
carbonate  of,  104;  decreases 
many  fungus  diseases,  107 ;  form 
to  use,  105;  forms  of,  104;  how 
to  find  out  when  soils  need  lime, 
104;  how  to  apply,  105;  mechani- 
cal action  of,  107 :  phosphates 
of,  81. 

Lime-kiln  ashes,   100. 

Linseed  meal,  old  and  new  process, 
51- 

Lobster   shells,    100. 

Afagnesium,  5  ;  carbonate  of,  103  ;  sul- 
phate of,  102. 


.Manganese,  5;   salts  of,   103. 

-Manures,  pulverized,  100;  see  farm 
manure. 

Marl,  99. 

Meat  meal,   54. 

Miscellaneous  fertilizer  materials, 
chapter   on,   98. 

Mora  meal,  61. 

Muck,  99. 

Muriate   of   potash,   91. 

Mussels,  100. 

Xitrate  of  soda,  58 ;  composition  and 
properties  of,  58. 

Nitrification,   22. 

Nitrogen,  2;  amounts  for  crops,  ta- 
ble of,  143 ;  excessive  nitrogen  in- 
vites disease,  68 ;  for  large  crops 
and  building  up  the  soil,  66;  for 
soils  well  supplied  and  long  grow- 
ing crops,  66;  forms  of,  48; 
functions  of,  67;  how  lost  from 
the  soil,  25,  26,  27 ;  organisms 
that  gather,  23 ;  utilization  of 
from  air,   58. 

Nitrogenous  materials,  high  grade, 
chapter  on,  48 ;  low  grade,  chap- 
ter on,  60 ;  availability  of,  6^ ; 
field  experiments  with,  63 ;  for 
immediate  results,  65 ;  kinds  to 
use,  65 ;  use  of  low  grade  in- 
creasing. 64;  value  of  low  grade, 
64. 

Odorless  phosphate,  see  basic  slag. 

One  crop  farming,  effect  on  fertili- 
ty,  28. 

Organic    matter,    13. 

Organic  nitrogen,  48,  49. 

Oxygen,   2. 

Peat,  9<)  :  for  bedding,  36  ;  absorption 
of,  37 :  dried,  6:^. 

Phosphates,  chapter  on,  70 ;  availa- 
bility of,  78 ;  available  deposits 
of,  y^i ;  classification  of,  77 ;  how 
they  occur,  70;  influence  of  soil 
on    availability    of,    78;    Florida 


54 


INDEX 


phosphates,  74;  form  to  use,  78; 
kind  to  use,  89;  mineral,  iz;  or- 
ganic, 70;  South  Carolina  phos- 
phates, TZ ;  Tennessee  phosphates, 

74- 

Phosphoric  acid,  80;  amount  in  soils, 
88;  available,  84;  difference  be- 
tween phosphates  and  superphos- 
phates, 83 ;  difference  of  the 
forms  of  in  superphosphates,  85 ; 
fixation  of,  88;  functions  of,  89; 
insoluble,  81;  loss  of,  28;  re- 
verted, 82;  soluble,  81;  value  of 
reverted,  83. 

Phosphorus,  4;  amount  for  crops, 
143- 

Physiological    water,   6. 

Plant  food,  amount  available  in  soils, 
15;  amount  removed  by  crops, 
14. 

Plants,  acids  and  bases  in,  9 : 
amounts  of  water  used  by,  7 : 
ash  of  young  and  mature,  12 ; 
ash  in,  10,  11.  12;  composition 
of,  6;  distribution  of  ash  in,  12: 
dry  matter  of,  8;  elements  that 
make  up,  10;  food  of,  6;  how 
benefited  by  open  soils,  19 ;  how 
they  feed,  5 ;  must  have  room, 
20;  occurrence  of  mineral  ele- 
ments in,  12 ;  require  oxygen, 
20;  salts  in,  10;  variation  of  ash 
in,  10;  variation  of  water  in,  7; 
water   in   young  and   mature,  8: 

Potash,  in  soils.  94 ;  chloride  of.  91  ; 
effects  maturity.  96;  effects  the 
leaves,  96;  favors  seed  and  straw 
formation,  96 ;  fixation  of,  95 ; 
forms  of,  95 ;  from  organic 
sources,  93 ;  functions  of,  96 ; 
helps  to  neutralize  plant  acids, 
97 ;  loss  of,  28 ;  sometimes  checks 
insect  pests  and  plant  diseases, 
97;    sulphate   of,  91. 

Potash    fertilizers,    chapter    on,   90. 


Potash-magnesia  carbonate,  93. 

Potash  manure  salts,  92. 

Potash   salts,  90. 

Potassium,  3 ;  amounts  for  crops,  143. 

Potassium   nitrate,    102. 

Powder   waste,    102. 

Preservatives  for  farm  manures,  44. 

Pulverized  manures,   100. 

Quick-lime,   104. 

Rice  hull  ashes,  loi. 

Rock  phosphates,  77. 

Rodunda  phosphate,   75. 

Rotations,  advantages  of,  30;  con- 
serves moisture,  34 ;  furnishes  a 
regular  income,  32 ;  furnishes 
feed  for  live-stock,  z^ ;  helps 
check  insect  and  plant  diseases, 
31  ;  helps  distribute  farm  labor, 
31;  keeps  down  weeds,  30;  leg- 
umes profitable  in,  31  ;  prevents 
losses  of  fertility.  ZZ  '•  regulates 
humus  supply,  34 ;  saves  ferti- 
lizer expenditure,  34;  utilization 
of  deep  and  shallow  rooted 
plants,  33 :  utilizes  plant  food 
more  evenly,   33. 

Salt,  common,  102. 

Salts  in  plants,   10. 

Sawdust  and  shavings  for  bedding, 
36 ;  absorptive  power  of  sawdust, 
37- 

Scutch,  61. 

Seaweed,  99. 

Sewage.   100. 

Sewage   sludge.    100. 

Sheep  manure.  38  '■  analysis  of,  39. 

Shoddies,  etc.,  62. 

Shrimp   waste,    100. 

Silicate  of   potash,    102.' 

Silicon,    4. 

Slaked  lime,  T04. 

Sodium,  5  I  chloride  of,  102 ;  sulphate 
of,    102. 

Soil  fertility,  chapter  on,  13;  factors 
influencing.   13:  loss  by  one  crop 


155 


fanning,  -'8;  loss  by  sjsteni  of 
farming,  34;  maintaining,  chap- 
ter on,   25. 

Soil  grains,  surface  area  of,  19. 

Soils,  biological  condition  of,  21  ; 
cracking  of,  19;  inoculation  of, 
23 ;  lumpy,  19 ;  mechanical  com- 
position of,  18;  plant  food  sup- 
ply of,  14;  puddling  of,  19;  phy- 
sical condition  of,  18;  tempera- 
ture of,  18;  thawing  and  freez- 
ing of,    19. 

Soot,   loi. 

Straw  as  bedding,  36;  absorptive 
power  of,  n. 

Street  sweepings,  loi. 

Sulphate  of  potash,  91. 

Sulphur,   4. 

Sulphuric  acid,  80;  manufacture  of, 
80. 

Superphosphates,  chapter  on,  80 ;  fav- 
oritism for  bone  superphosphates, 
86;  how  to  make  at  home,  88; 
manufacture  of,  80;  names  ap- 
plied to,  84 ;  no  free  acid  in,  87 ; 


the  difference  between  phosphates 
and  superphosphates,  83;  the  dif- 
ference of  the  forms  of  phos- 
phoric acid   in,  81,  82,  83,  85. 

Sylvinit,  91. 

Tankage,  53 ;  grades  of,  53 ;  varia- 
tion in,   53. 

Thomas  phosphate  powder,  see  basic 
slag. 

Tobacco  stems  and  stalks,  94. 

Trade  values  of  fertilizers,  123 ;  dis- 
cussion of  table  of,  124;  how 
obtained,  124. 

Tubercles,  3. 

Unit  system  of  purchase  of  fertiliz- 
ers, 114. 

Valuation  of  fertilizers,  chapter  on, 
119. 

\'alues,  agricultural  and  commercial, 
121,  122;  trade,  123. 

Water  in  plants,  6,  7,  8. 

Wood  ashes,  93 ;  value  of,  93. 

Wood  waste,  shoddies,  etc.,  62 ; 
treated,  62. 


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